2.8/9 × 15/36 + 1/27 = 1 1/27
3. 12× 5/6 – 2/9 ×3 = 28/3
4.8× 5/4 + 1/4 = 4 1/4
5.6÷ 3/8 – 3/8 ÷6 = 255/ 16
6.4/7 × 5/9 + 3/7 × 5/9 = 5/9
7.5/2 -( 3/2 + 4/5 ) = 1/5
8.7/8 + ( 1/8 + 1/9 ) = 10/9
9.9 × 5/6 + 5/6 = 25/3
10.3/4 × 8/9 - 1/3 = 1/3
1 1.7 × 5/49 + 3/ 14 = 13/ 14
12.6 ×( 1/2 + 2/3 )= 7
13.8 × 4/5 + 8 × 1 1/5 = 24
14.3 1 × 5/6 – 5/6 = 25
15.9/7 - ( 2/7 – 10/2 1 )= 3 1/2 1
16.5/9 × 18 – 14 × 2/7 = 6
17.4/5 × 25/ 16 + 2/3 × 3/4 = 7/4
18. 14 × 8/7 – 5/6 × 12/ 15 = 46/3
19. 17/32 – 3/4 × 9/24 = 13/ 16
20.3 × 2/9 + 1/3 = 1
2 1.5/7 × 3/25 + 3/7 = 18/35
22.3/ 14 × 2/3 + 1/6 = 13/42
23. 1/5 × 2/3 + 5/6 = 29/30
24.9/22 + 1/ 1 1 ÷ 1/2 = 13/22
25.5/3 × 1 1/5 + 4/3 = 5
26.45 × 2/3 + 1/3 × 15 = 35
27.7/ 19 + 12/ 19 × 5/6 = 17/ 19
28. 1/4 + 3/4 ÷ 2/3 = 1 1/8
29.8/7 × 2 1/ 16 + 1/2 = 2
30. 10 1 × 1/5 – 1/5 × 2 1 = 16
3 1.50+ 160÷40 (58+360)÷(64-45) = 138
32. 120- 144÷ 18+35 = 147
33.347+45×2-4 160÷52 = 357
34(58+37)÷(64-9×5) = 5
35.95÷(64-45) = 5
36. 178- 145÷5×6+42 = 46
37.8 12-700÷(9+3 1× 1 1)= 8 10
38.85+ 14×( 14+208÷26) = 393
39.(284+ 16)×(5 12-8208÷ 18)= 16800
40. 120-36×4÷ 18+35 = 147
4 1.(58+37)÷(64-9×5) = 5
42.(6.8-6.8×0.55)÷8.5 = 0.36
43.0. 12× 4.8÷0. 12×4.8 = 23.04
44.(3.2× 1.5+2.5)÷ 1.6 = 4.5625
45.6- 1.6÷4 = 5.6
46.7.2÷0.8- 1.2×5 = 3
47.6.5×(4.8- 1.2×4)= 0
48. 10. 15- 10.75×0.4-5.7 = 0. 15
49.5.8×(3.87-0. 13)+4.2×3.74 = 37.4
50.32.52-(6+9.728÷3.2)×2.5 = 9.92
5 1.-5+58+ 13+90+78-(-56)+50 = 340
52.-7*2-57/3 = -33
53.(-7)*2/( 1/3)+79/(3+6/4) = 59.556
54. 123+456+789+98/(-4) = 1343.5
55.369/3-(-54-3 1/ 15.5) = 179
56.39+{ 3x[42/2x(3x 8)]} = 155 1
57.9x8x7/5x(4+6) = 1008
58. 1 1x 22/(4+ 12/2)= 24.2
59.94+(-60)/ 10 = 100
8-channel factorization
1.
a^3-2b^3+ab(2a-b)
=a^3+2a^2b-2b^3-ab^2
=a^2(a+2b)-b^2(2b+a)
=(a+2b)(a^2-b^2)
=(a+2b)(a+b)(a-b)
2.
(x^2+y^2)^2-4y(x^2+y^2)+4y^2
=(x^2+y^2-2y)^2
3.
(x^2+2x)^2+3(x^2+2x)+x^2+2x+3
=(x^2+2x)^2+4(x^2+2x)+3
=(x^2+2x+3)(x^2+2x+ 1)
=(x^2+2x+3)(x+ 1)^2
4.
(a+ 1)(a+2)+(2a+ 1)(a-2)- 12
=a^2+3a+2+2a^2-3a-2- 12
=3a^2- 12
=3(a+2)(a-2)
5.
x^2(y+z)^2-2xy(x-z)(y+z)+y^2(x-z)^2
=[x(y+z)-y(x-z)]^2
=(xz+yz)^2
=z^2(x+y)^2
6.
3(a+2)^2+28(a+2)-20
=[3(a+2)-2][(a+2)+ 10]
=(3a+4)(a+ 12)
7.
(a+b)^2-(b-c)^2+a^2-c^2
=(a+b)^2-c^2+a^2-(b-c)^2
=(a+b+c)(a+b-c)+(a+b-c)(a-b+c)
=(a+b-c)(a+b+c+a-b+c)
=2(a+b-c)(a+c)
8.
x(x+ 1)(x^2+x- 1)-2
=(x^2+x)(x^2+x- 1)-2
=(x^2+x)^2-(x^2+x)-2
=(x^2+x-2)(x^2+x+ 1)
=(x+2)(x- 1)(x^2+x+ 1)
1. 125*3+ 125*5+25*3+25
2.9999*3+ 10 1* 1 1*( 10 1-92)
3.(23/4-3/4)*(3*6+2)
4.3/7 × 49/9 - 4/3
5.8/9 × 15/36 + 1/27
6. 12× 5/6 – 2/9 ×3
7.8× 5/4 + 1/4
8.6÷ 3/8 – 3/8 ÷6
9.4/7 × 5/9 + 3/7 × 5/9
10.5/2 -( 3/2 + 4/5 )
1 1.7/8 + ( 1/8 + 1/9 )
12.9 × 5/6 + 5/6
13.3/4 × 8/9 - 1/3
14.7 × 5/49 + 3/ 14
15.6 ×( 1/2 + 2/3 )
16.8 × 4/5 + 8 × 1 1/5
17.3 1 × 5/6 – 5/6
18.9/7 - ( 2/7 – 10/2 1 )
19.5/9 × 18 – 14 × 2/7
20.4/5 × 25/ 16 + 2/3 × 3/4
2 1. 14 × 8/7 – 5/6 × 12/ 15
22. 17/32 – 3/4 × 9/24
23.3 × 2/9 + 1/3
24.5/7 × 3/25 + 3/7
25.3/ 14 ×× 2/3 + 1/6
26. 1/5 × 2/3 + 5/6
27.9/22 + 1/ 1 1 ÷ 1/2
28.5/3 × 1 1/5 + 4/3
29.45 × 2/3 + 1/3 × 15
30.7/ 19 + 12/ 19 × 5/6
3 1. 1/4 + 3/4 ÷ 2/3
32.8/7 × 2 1/ 16 + 1/2
33. 10 1 × 1/5 – 1/5 × 2 1
34.50+ 160÷40
35. 120- 144÷ 18+35
36.347+45×2-4 160÷52
37(58+37)÷(64-9×5)
38.95÷(64-45)
39. 178- 145÷5×6+42
40.8 12-700÷(9+3 1× 1 1)
4 1.85+ 14×( 14+208÷26)
43. 120-36×4÷ 18+35
44.(58+37)÷(64-9×5)
45.(6.8-6.8×0.55)÷8.5
46.0. 12× 4.8÷0. 12×4.8
47.(3.2× 1.5+2.5)÷ 1.6
48.6- 1.6÷4= 5.38+7.85-5.37=
49.7.2÷0.8- 1.2×5= 6- 1. 19×3-0.43=
50.6.5×(4.8- 1.2×4)=
5 1.5.8×(3.87-0. 13)+4.2×3.74
52.32.52-(6+9.728÷3.2)×2.5
53.[(7. 1-5.6)×0.9- 1. 15] ÷2.5
54.5.4÷[2.6×(3.7-2.9)+0.62]
55. 12×6÷( 12-7.2)-6
56. 12×6÷7.2-6
57.0.68× 1.9+0.32× 1.9
58.58+370)÷(64-45)
59.420+580-64×2 1÷28
60. 136+6×(65-345÷23)
15- 10.75×0.4-5.7
62. 18. 1+(3-0.299÷0.23)× 1
63.(6.8-6.8×0.55)÷8.5
64.0. 12× 4.8÷0. 12×4.8
65.(3.2× 1.5+2.5)÷ 1.6
66.3.2×6+( 1.5+2.5)÷ 1.6
67.0.68× 1.9+0.32× 1.9
68. 10. 15- 10.75×0.4-5.7
69.5.8×(3.87-0. 13)+4.2×3.74
70.32.52-(6+9.728÷3.2)×2.5
7 1.[(7. 1-5.6)×0.9- 1. 15] ÷2.5
72.5.4÷[2.6×(3.7-2.9)+0.62]
73. 12×6÷( 12-7.2)-6
74. 12×6÷7.2-6
75.33.02-( 148.4-90.85)÷2.5
1) 76.(25%-695%- 12%)*36
77./4*3/5+3/4*2/5
78. 1- 1/4+8/9/7/9
79.+ 1/6/3/24+2/2 1
80./ 15*3/5
8 1.3/4/9/ 10- 1/6
82./3+ 1/2)/5/6- 1/3]/ 1/7
83./5+3/5/2+3/4
84.(2-2/3/ 1/2)]*2/5
85.+5268.32-2569
86.3+456-52*8
87.5%+6325
88./2+ 1/3+ 1/4
2) 89+456-78
3) 5%+.3/7 × 49/9 - 4/3
4) 9 × 15/36 + 1/27
5) 2× 5/6 – 2/9 ×3
6) 3× 5/4 + 1/4
7) 94÷ 3/8 – 3/8 ÷6
8) 95/7 × 5/9 + 3/7 × 5/9
9) 6/2 -( 3/2 + 4/5 )
10) 8 + ( 1/8 + 1/9 )
1 1) 8 × 5/6 + 5/6
12) 1/4 × 8/9 - 1/3
13) 10 × 5/49 + 3/ 14
14) 1.5 ×( 1/2 + 2/3 )
15) 2/9 × 4/5 + 8 × 1 1/5
16) 3. 1 × 5/6 – 5/6
17) 4/7 - ( 2/7 – 10/2 1 )
18) 19 × 18 – 14 × 2/7
19) 5 × 25/ 16 + 2/3 × 3/4
20) 4 × 8/7 – 5/6 × 12/ 15
2 1) 7/32 – 3/4 × 9/24
22) 1、 2/3÷ 1/2- 1/4×2/5
2、 2-6/ 13÷9/26-2/3
3、 2/9+ 1/2÷4/5+3/8
4、 10÷5/9+ 1/6×4
5、 1/2×2/5+9/ 10÷9/20
6、 5/9×3/ 10+2/7÷2/5
7、 1/2+ 1/4×4/5- 1/8
8、 3/4×5/7×4/3- 1/2
9、 23-8/9× 1/27÷ 1/27
10、 8×5/6+2/5÷4
1 1、 1/2+3/4×5/ 12×4/5
12、 8/9×3/4-3/8÷3/4
13、 5/8÷5/4+3/23÷9/ 1 1
23) 1.2×2.5+0.8×2.5
24) 8.9× 1.25-0.9× 1.25
25) 12.5×7.4×0.8
26) 9.9×6.4-(2.5+0.24)(27) 6.5×9.5+6.5×0.5
0.35× 1.6+0.35×3.4
0.25×8.6×4
6.72-3.28- 1.72
0.45+6.37+4.55
5.4+6.9×3-(25-2.5)2×4 1846-620-380
4.8×46+4.8×54
0.8+0.8×2.5
1.25×3.6×8×2.5- 12.5×2.4
28× 12.5- 12.5×20
23.65-(3.07+3.65)
(4+0.4×0.25)8×7× 1.25
1.65×99+ 1.65
27.85-(7.85+3.4)
48× 1.25+50× 1.25×0.2×8
7.8×9.9+0.78
( 10 10+309+4+68 1+6)× 12
3×9 146×782×6×854
5. 15×7/8+6. 1-0.60625
1.3/7 × 49/9 - 4/3
2.8/9 × 15/36 + 1/27
3. 12× 5/6 – 2/9 ×3
4.8× 5/4 + 1/4
5.6÷ 3/8 – 3/8 ÷6
6.4/7 × 5/9 + 3/7 × 5/9
7.5/2 -( 3/2 + 4/5 )
8.7/8 + ( 1/8 + 1/9 )
9.9 × 5/6 + 5/6
10.3/4 × 8/9 - 1/3
1 1.7 × 5/49 + 3/ 14
12.6 ×( 1/2 + 2/3 )
13.8 × 4/5 + 8 × 1 1/5
14.3 1 × 5/6 – 5/6
15.9/7 - ( 2/7 – 10/2 1 )
16.5/9 × 18 – 14 × 2/7
17.4/5 × 25/ 16 + 2/3 × 3/4
18. 14 × 8/7 – 5/6 × 12/ 15
19. 17/32 – 3/4 × 9/24
20.3 × 2/9 + 1/3
2 1.5/7 × 3/25 + 3/7
22.3/ 14 ×× 2/3 + 1/6
23. 1/5 × 2/3 + 5/6
24.9/22 + 1/ 1 1 ÷ 1/2
25.5/3 × 1 1/5 + 4/3
26.45 × 2/3 + 1/3 × 15
27.7/ 19 + 12/ 19 × 5/6
28. 1/4 + 3/4 ÷ 2/3
29.8/7 × 2 1/ 16 + 1/2
30. 10 1 × 1/5 – 1/5 × 2 1
3 1.50+ 160÷40 (58+370)÷(64-45)
32. 120- 144÷ 18+35
33.347+45×2-4 160÷52
34(58+37)÷(64-9×5)
35.95÷(64-45)
36. 178- 145÷5×6+42 420+580-64×2 1÷28
37.8 12-700÷(9+3 1× 1 1) ( 136+64)×(65-345÷23)
38.85+ 14×( 14+208÷26)
39.(284+ 16)×(5 12-8208÷ 18)
40. 120-36×4÷ 18+35
4 1.(58+37)÷(64-9×5)
42.(6.8-6.8×0.55)÷8.5
43.0. 12× 4.8÷0. 12×4.8
44.(3.2× 1.5+2.5)÷ 1.6 (2)3.2×( 1.5+2.5)÷ 1.6
45.6- 1.6÷4= 5.38+7.85-5.37=
46.7.2÷0.8- 1.2×5= 6- 1. 19×3-0.43=
47.6.5×(4.8- 1.2×4)= 0.68× 1.9+0.32× 1.9
48. 10. 15- 10.75×0.4-5.7
49.5.8×(3.87-0. 13)+4.2×3.74
50.32.52-(6+9.728÷3.2)×2.5
5 1.[(7. 1-5.6)×0.9- 1. 15] ÷2.5
52.5.4÷[2.6×(3.7-2.9)+0.62]
53. 12×6÷( 12-7.2)-6 (4) 12×6÷7.2-6
102×4.5
7.8×6.9+2.2×6.9
5.6×0.25
8×(20- 1.25)
1) 127+352+73+44 (2)89+276+ 135+33
( 1)25+7 1+75+29 +88 (2)243+89+ 1 1 1+57
9405-2940÷28×2 1
920- 1680÷40÷7
690+47×52-398
148+3328÷64-75
360×24÷32+730
2 100-94+48×54
5 1+(2304-2042)×23
42 15+(436 1-7 16)÷8 1
(247+ 18)×27÷25
36-720÷(360÷ 18)
1080÷(63-54)×80
(528+9 12)×5-6 178
8528÷4 1×38-904
264+3 18-8280÷69
( 174+209)×26- 9000
8 14-(278+322)÷ 15
1406+735×9÷45
3 168-7828÷38+504
796-5040÷(630÷7)
285+(3000-372)÷36
1+5/6- 19/ 12
3x(-9)+7x(-9
(-54)x 1/6x(- 1/3)
1. 18. 1+(3-0.299÷0.23)× 1
2.(6.8-6.8×0.55)÷8.5
3.0. 12× 4.8÷0. 12×4.8
4.(3.2× 1.5+2.5)÷ 1.6 (2)3.2×( 1.5+2.5)÷ 1.6
5.6- 1.6÷4= 5.38+7.85-5.37=
6.7.2÷0.8- 1.2×5= 6- 1. 19×3-0.43=
7.6.5×(4.8- 1.2×4)= 0.68× 1.9+0.32× 1.9
8. 10. 15- 10.75×0.4-5.7
9.5.8×(3.87-0. 13)+4.2×3.74
10.32.52-(6+9.728÷3.2)×2.5
1 1.[(7. 1-5.6)×0.9- 1. 15] ÷2.5
12.5.4÷[2.6×(3.7-2.9)+0.62]
13. 12×6÷( 12-7.2)-6
14. 12×6÷7.2-6
15.33.02-( 148.4-90.85)÷2.5
Smart question
Party A and Party B do math problems together. If A did as many questions as B, and B did 6, how many did A do? How many questions did b do?
2. Tourists paddle upstream from the wharf 10 at 15, and they are required to return no later than 13 on the same day, knowing that the current speed is 1.4 km/h and the speed of the ship in still water is 3 km/h. If tourists rest every 30 minutes/kloc,
3. There are two scoring methods for a math contest: the first one gets 5 points for a correct answer, 2 points for a wrong answer, and no deduction for a wrong answer; The second method, give 40 points first, give 3 points for one correct answer, give no points for one wrong answer, and deduct 1 point. A student got 8 1 point for both methods. How many questions are there in this competition?
4. The construction team should build a canal: 8 meters more every day, which can be completed 4 days in advance; If it is repaired 8 meters less every day, the completion will be delayed by 4 days. Can you tell me how long this canal is?
Two-thirds (two-thirds) of a batch of grain was transported away, which was 1 ton less. At this time, the ratio of surplus grain to raw grain is 3:5. How many tons was this grain originally?
Divide the two baskets of apples into three categories: A, B and C. Category A gets 2/5 of the total, and the rest is distributed to categories B and C according to 5: 7. It is known that the weight of the second basket of apples is 9/ 10 of that of the first basket, which is 5 kg less than that of the first basket. Apples shared by Class A, Class B and Class C are _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
3. Let A and B make a2000b with 6 digits divisible by 26. All such six digits are _ _ _ _ _.
4. Cut the 8×8 square paper on the right side into four figures with the same shape and size along the grid line, so that each one has the words Luo, Niu and Shan. Draw the result of cutting with a solid line on the diagram.
5. A container filled with salt water. The teacher asked Xiao Qiang to pour 800g of 5% salt water to make 20% salt water. But Xiao Qiang mistakenly poured 800 grams of water. After the teacher found it, he said, Never mind, pour 400 grams of salt water for the third time into the container, and you can get 20% salt water. Then the concentration of the third brine is _ _ _ _ _ _ _%.
6. Set 6 pockets to hold 18, 19, 2 1, 23, 25 and 34 balls respectively. Xiao Wang took three of them and Xiao Li took the other two. If Xiao Wang gets twice as many balls as Xiao Li, then Xiao Wang gets _ _ _ _ _ _ _.
7. A pool is equipped with two water pipes, A and B. The hourly displacement of pipe B is 75% of that of pipe A. First, pipe B is used to drain water for 5 hours, and then pipe A is used to drain water. As a result, the water in the pool is emptied 1 hour earlier than that of pipe B alone. If 120 tons of water is drained by the second pipe, the water in the pool can be drained 2 hours earlier than that by only using the second pipe. So the original water in the pool is _ _ _ _ _ _ _ tons.
8. In the picture on the right, the quadrangles FMCG and FDHG are trapezoidal. D is the midpoint of BC, BE= BA, MF= MA, and the area of △ABC is 1. Then the area of trapezoidal FDHG is _ _ _ _ _ _ _.
9. Three cars, A, B and C, travel from City A to City B at the same speed. Car A had an accident after driving 1 hour, and cars B and C drove as usual. After a car stopped for half an hour, it continued to move at 4/5 of its original speed. Two cars, B and C, went to a city 200 kilometers away. Car B had an accident and car C was driving as usual. After stopping for half an hour, car B continued to drive at 4/5 of its original speed. Results The time to arrive in B city was earlier than that of B train 1 hour, and B train was earlier than that of A train 1 hour. The distance between city A and city B is _ _ _ _ _ _ _ kilometers.
10. There are _ _ _ _ _ _ different triangles in the * * on the right.
1 1. Suppose that in four arrays composed of four different positive integers, the sum of the smallest number and the average of the other three numbers is 17, while the sum of the largest number and the average of the other three numbers is 29. In the four arrays that meet the above conditions, the maximum number is _ _ _ _ _ _ _.
12. The number ratio of the first and second construction teams is 3: 4, and the efficiency ratio of each person is 5: 4. Two teams accepted two projects with the same workload and conditions at the same time. As a result, the second team finished 9 days earlier than the first team. Later, two-thirds of the workers in the first team and two-thirds of the workers in the second team13 formed a new team, and the rest of the workers formed a new team. At the same time, two new teams accepted two projects with exactly the same workload and conditions. Therefore, the new team 2 finished six days earlier than the new team 1. Then the ratio of the workload of the two projects before and after is _ _ _ _ _ _.
relay race
1.Class A and Class B each have a library with 303 books. It is known that 5/ 13 of A-type books and 1/4 of B-type books together form 95 books, so A-type books have _ _ _ _ _ _.
2. Let the sum of the digits of the answers to the above questions be a. The clock in Xiao Ning and the clock in the school go normally, but the clock in Xiao Ning is fast and the clock in the school is accurate. Xiao Ning left home for school at 8: 00 at home. When she arrived at school, the school clock was 7: 50. Go home after school at noon, according to the school clock 12. When he got home, the clock at home was exactly 12: 34. If Xiao Ning spends the same time on his way to and from school, then Xiao Ning's clock will be set forward by _ _ _ _ _ _ _ _ minutes.
3. Set the number of answers to the above questions as b, as shown in the figure, there is a rectangle with a length of b/4 and a width of 1 in the big square. The vertices of the rectangle are all on the side of the square, and the symmetry axis of the rectangle coincides with the diagonal of the square, so the area of the square is _ _ _ _ _.
4. Let the integer part of the number of answers to the above questions be c, and if 1/c is expressed as the sum of two different decimal units, then * * * has _ _ _ _ different representations (only different summation orders are regarded as one).
5. Let the number of answers to the above questions be D. When Wang Li is as old as thomas lee, Liu Qiang is D years younger than the sum of Wang Li and thomas lee. When Liu Qiang is now as old as Wang Li, Wang Li was _ _ _ _ _ _ _ _.
6. If the number of answers to the above questions is set to E, all four numbers consisting of 2, 3, 5 and E (numbers are allowed to be repeated) will be arranged in a column from small to large, and the 56th number in this column is _ _ _ _ _ _ _ _.
7. Let the unit number of the answers to the above questions be f, and there are 10 integers arranged in a circle. Replace each integer with the average of two adjacent numbers, and the result is shown in the figure. Then the original number of the position occupied by the number f in the figure is _ _ _ _ _ _ _.
8. Let 2 times the number of answers to the above questions be g. There are a set of positive integers, in which the g times of the difference between any two numbers is not less than their product. Then this set of positive integers has at most _ _ _ _ _ _ _.
1. There are 28 children waiting in line. The number from the left 10 is Aihua. What's the number on his right?
2. new york time is HK time minus 13 hours. You have an appointment with a friend in new york to call him at 8 pm on April 1 new york time. When should you call him in Hong Kong?
A worker can process 90 parts in 5 hours. /kloc-how many workers does it take to process 540 parts in 0/0 hour?
4. How many integers greater than 100 have the same quotient and remainder after dividing by 13?
5. Four rooms, with no less than two people in each room and no less than eight people in any three rooms. How many people are there in these four rooms?
6. The divisor (or factor) of1998 has two digits, which is the largest?
7. In the English exam, Xiao Ming scored an average of 88 points in the first three times. How many points does he get if he wants to average 90 points for the fourth time?
8. There are at most five Sundays in a month. 12 What are the months with five Sundays in a year?
9. Choose six of the ten numbers 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9, and fill in the following boxes to make the formula hold. Each box is filled with a number, and the number in each box is different.
□ +□□ =□□□
What is the largest three digits in the formula?
10. A number is six digits, the first four digits are 2857, and the last two digits are unclear, namely
2857□□
But I remember it can be divisible by 1 1 and 13. Please work out the last two figures.
1 1. A school has 5 18 students. If the number of boys increases by 4% and the number of girls decreases by 3, the total number will increase by 8. So how many more boys than girls?
12. Chen Min wants to go shopping three times. 5 yuan, 2 yuan, 1 yuan, how many coins should I bring * * * so that I don't generate any change below 10 yuan at a time?
(There are only three kinds of coins: 5 yuan, 2 yuan, 1 yuan. )
13. The figure on the right is a graph composed of three semicircles, in which the diameter of the small circle is 8 and the diameter of the middle circle is 12.
14. The kindergarten teacher sent some pictures to Class A, Class B and Class C, and everyone can get 6 pictures. If it is only Grade B, everyone can get 15 pictures. If it is only Grade C, everyone can get 14 pictures. If it is Class A, how many photos can each person get?
15. Two people play a game: take turns to count off, and the count off can only be 1, 2, 3, 4, 5, 6, 7, 8. Add up the figures reported by two people. After the number is reported, the plus sign is 123, and the winner will give priority to the number.
16. The page number of the novel must be printed in the font of 1989. 1 How many times does this number appear in the page number of this book?
What are the last four digits of the sum of 17.23: 3, 33, 333, …, 33…3(23 3s)?
18. Arrange the eight numbers 1, 1, 2, 2, 3, 4, 4 into an eight-digit number, so that there is a number between two 1, two numbers between two 2, three numbers between two 3 and two 4. So, here's the thing.
19. Take at most a few numbers from the natural number 1, 2, 3, …, 2004, 2005, so that the difference between every two numbers is not equal to 4?
20. There is a six-digit telephone number, in which the three digits on the left are the same, and the three digits on the right are three consecutive natural numbers, and the sum of the six digits is exactly equal to the last two digits. What's the phone number?
2 1. If a is a natural number, prove 10 │ (A2005-A 1949).
22. Give 12 different two-digit numbers, and prove that two numbers can be selected from them, and their difference is a two-digit number composed of two identical numbers.
23. Find the smallest three digits of 2 divided by 3, 3 divided by 5 and 5 divided by 7.
24. Let 2n+ 1 be a prime number, and prove that:12,22, …, n2 is divided by 2n+ 1 to get different remainders.
25. The difference between the sum of squares of prime numbers not less than 5 1 will be divisible by 24.
26. There are two kinds of sugar water, A contains 270g of sugar, 30g of water, B contains 400g of sugar, and water100g. Now we want to get100g of 82.5% sugar water. How many grams should we take from everyone?
27. A container contains 65,438+00 liters of pure alcohol. After pouring out 1 l, fill it with water, then pour out 1 l, and then pour out 1 l. What is the concentration of alcohol solution in the container?
28. A few kilograms of 4% salt water evaporated part of the water and became 10% salt water. After adding 300 grams of 4% salt water, it becomes 6.4% salt water. How many kilograms was the original salt water?
29. It is known that a few grams of brine, after adding a certain amount of water for the first time, the concentration of brine becomes 3%, and after adding the same amount of water for the second time, the concentration of brine becomes 2%. Add the same amount of water for the third time to find the concentration of brine.
30. There are three kinds of brines, A, B and C, which are mixed according to the quantity ratio of A to B of 2: 1 to obtain brines with the concentration of 13%; According to the mass ratio of A to B 1: 2, the brine with the concentration of 14% was obtained; According to the mass ratio of A, B and C 1: 1: 3, the brine with the concentration of 10.2% was obtained. What is the concentration of brine C?
[answer]
1. From the right, it is 19.
2. April 2 at 9: 00 a.m.
3.9 workers.
There are five.
13× 7+7 = 98 < 100, and the quotient starts from 8. But the remainder is less than 13, and the maximum is 12, where13× 8+8 =112,655. 13× 10+ 10 = 140, 13× 1 1+ 1 1 = 154, 65438.
5. At least 1 1 person.
There are at least 3 people in the room with the largest number of people, and at least 8 people in the other three rooms, with a total of at least 1 1 person.
6. The largest two-digit divisor is 74.
1998= 2× 3× 3× 3× 37
7. Get at least 96 points in the fourth test.
88+(90-88) × 4 = 96 (point)
8. There are at most five Sundays in five months.
65438+ 10/month 1 is a Sunday, and there are 53 Sundays throughout the year. There are at least 4 Sundays in each month, 53-4× 12=5, and 5 months is five more Sundays.
9. 105.
The first two digits of the total are 1 and 0, and the tenth digit of the two digits is 9. Therefore, the maximum digits of addend are 7 and 8.
10. The last two digits are 14.
285700 ÷ (11×13) =1997 Yu 129.
The remainder 129 plus 14 is divisible by 143.
1 1. There are 32 more boys than girls.
4% of boys are 3+8 = 1 1 (person), boys are 1 1 ÷ 4% = 275 (person), and girls are 5 18-275=243 (person).
12. At least 5 yuan, 2 yuan, 1 yuan coin *** 1 1.
To shop three times, you must have three 5 yuan, three 2 yuan and three 1 yuan. To cope with three 4 yuan, you must have at least two coins, such as 2 yuan and 1 yuan. So the total 1 1 is indispensable. Prepare three 5 yuan and five 2 yuan, and 1 Yuan 3.
14.A class can get 35 tickets each.
Suppose the total number of three classes is 1, then the number of class B is 6/ 15, and the number of class C is 6/ 14, then the number of class A is:
15. The first number is 6.
The other party must quote at least 1 and at most 8. No matter what the other party reports, you can always add up the reports of two people.
123÷ 9= 13…… 6.
Your first count. 6. Later, after the other party reports, you report again, so that the sum of the two people's reports in one round is 9, and it can reach 123 after three rounds.
16.4
17.A 26 days and a half, B 40 days
18.2 1
19. 14 and 1/3.
20. 10
21.The distance between A and B is 540 kilometers, and the original train speed is 90 kilometers per hour.
22.750
23.384
24.600
25. There are 48 students in Class One and 42 students in Class Two.
26. 15
27.82
28.3 12
29. At least five and at most seven.
30.784
5. 1. A factory originally used iron sheets with a length of 4m and a width of 1 m to enclose a cube-shaped bottomless product storage place (with other materials for the bottom and top), which was just enough to store products for one week. Now that the number of products has increased by 27%, can we still enclose the storage place with the original iron sheet to hold the products of the week?
2. For a project, it takes 10 days for Party A to do it alone, and 15 days for Party B to do it alone. If two people cooperate, the work efficiency will be reduced. Party A can only complete the original 4/5, and Party B can only complete the original 9/65,438+00. It takes eight days to complete the project now, and the fewer days two people work together, the better. So how many days will they cooperate?
A car travels from city A to city B at a speed of 40 kilometers per hour. When it returned, it traveled 3/4 of the whole journey at the original speed, which is more than 5 kilometers. Then it travels at a speed of 30 kilometers per hour to complete the rest of the journey. So it takes more time to go back to city A than to city B 10 minutes. How far is the distance between city A and city B?
4. The charging standard of tap water for residents in a city is: the monthly water consumption of each household is less than 4 tons, per ton 1.8 yuan. When it exceeds 4 tons, the excess part is 3.00 yuan per ton. One month, two households, A and B, paid a water fee of 26.40 yuan, and the water consumption ratio was 5:3. Please calculate how much water each household has to pay.
Dude, I'm really sorry. That's all I found. You should also practice word problems.