1. Three large bottles and five small bottles can hold 5.6 kilograms of ink, and one large bottle and three small bottles can hold 2.4 kilograms of ink. Then 1 large bottle and 2 small bottles can hold () kilograms of ink.
Together, 4 big 8 small bags 5.6+2.4=8, so 1 big 2 small bags 8/4 = 2kg.
2. Four students, A, B, C and D, took part in the Olympic Mathematical Examination. A got 74 points, B got 86 points and C got 96 points. The average score of the four students is exactly an integer. How many points can a D get?
74/4 remainder 2, 86/4 remainder 2, 96/4 is an integer, and 2+2=4 is divisible by 4. So the d score should be a multiple of 4,4n (n=0, 1, 2. . . 25)
3. In □× 5 ÷ 3× 9+11=1991,the number to be filled in is ().
( 199 1- 1 1) ÷9×3÷5= 1980÷ 15= 132
4. There are two red flags and 1 blue flag. These flags have the same size and shape. Hang these flags on the flagpole to make various signals, and each flag is arranged at a certain interval. How many different signals can these flags express?
Only blue: 3
Only one side is red: 3
Only two sides are red: 3
1 red 1 blue: 3*2=6
2 red 1 blue: 3
3*6= 18
5, a basket of apples, if divided equally to 4 children, 3 more apples; If you divide it equally among five children, there will be four more apples; If it is distributed to six children on average, there will be less 1 apple. There are at least () apples in this basket.
Equivalent to 4n- 1, 5m- 1, 6x- 1.
Find the least common multiple of 4, 5 and 6, and then-1.
The least common multiple of 4, 5 and 6 is 60, so there are at least 60- 1=59 apples.
6. The distance between Party A and Party B is 360 kilometers, and buses and trucks leave from Party A for Party B at the same time. The speed of the truck is 60 kilometers per hour and the speed of the bus is 40 kilometers per hour. After the truck arrives at the second place, it stays for 0.5 hours and returns to the first place at the original speed. A few hours after starting from the first place, the two cars met.
It took 360/60=6 hours for the truck to arrive at B. 0.5 hours later, the bus * * * traveled 6.5 * 40 = 260km, starting from B at 360-260 =100km, and then 100/(40+60) = 65438.
7. A number is divided by more than 2 by 3, more than 3 by 4, and more than 4 by 5. The minimum number is ()
Like the fifth question, find the least common multiple of 3, 4 and 5, and then-1. The least common multiple of 3,4,5 is 60,60-1= 59.
8. Greening workers planted a tree every 4 meters on both sides of a section of highway, and planted 74 trees in a row. Now we must plant a tree every 6 meters. How many trees don't need transplanting?
74/2= 37 trees per side
Each side (37- 1) * 4 = 144m.
The least common multiple of 4 and 6 is 12, so 0,12,24. . . . There is no need to transplant144m, * * 13 trees, but 37- 13=24 trees.
24*2=48 trees need to be transplanted on both sides.
9. Students from Class 5 (4) of Binhai Experimental Primary School went for a picnic. When eating, every two people have a rice bowl, every three people have a vegetable bowl and every four people have a soup bowl. A total of 65 bowls are used. How many students are there in this class?
The least common multiple of 2,3,4 is 12. 6 rice bowls, 4 vegetable bowls, 3 soup bowls, * * * 12 people.
65/ 13=5 groups, so the number of students is 5* 12=60.
10. The telephone charges of a county are as follows: 0 ~ 3 minutes in 0.2 yuan, more than 3 minutes, the excess is calculated at 0./kloc-0 yuan per minute (less than 1 minute is calculated at 1 minute), and Xiaojun calls the county for 7 minutes and 35 seconds to calculate the telephone charges.
0.2+(8-3)*0. 1=0.7 yuan.