Solution:
We can divide four two-digit numbers into four tens and four digits. In order to maximize the sum, we must first meet the maximum number of every ten digits in order to maximize the sum. So ten digits take 4, 5, 6, 7, one digit takes 0, 1, 2, 3, and the sum of the four two digits is 226.
A: The sum of the four digits is 226.
Question 1. The clerk changed a 5 yuan RMB and a 50-cent RMB into 28 yuan RMB with face values of 1 yuan and 1 respectively. How much RMB do you want?
Question 2: There are 50 RMB * * with total face value 1 16 yuan. As we all know, one yuan is more than two yuan. How many RMB are there in three denominations?
Question 3: There are 400 movie tickets from 3 yuan, 5 yuan and 7 yuan, with a value of 1920 yuan, among which 7 yuan and 5 yuan have equal tickets. How many movie tickets are there for each of the three prices?
Question 4: Two kinds of cars are used to transport goods. Each car contains 18 boxes, and each car contains 12 boxes. Now there is a 18 car, worth 3024 yuan. If each case is cheap in 2 yuan, the goods are worth 2520 yuan. Q: How many cars are there?
Question 5. A truck can transport ore 20 times a day in sunny days and 12 times a day in rainy days. Transportation 1 12 times a day, with an average of 14 times a day. How many days are it rainy these days?
Question 6. A batch of watermelons has been delivered and will be sold in two categories, the large one in 0.4 yuan and the small one in 0.3 yuan. In this way, these watermelons are worth 290 yuan. If the price per kilogram of watermelons is reduced by 0.05 yuan, this batch of watermelons can only be sold in 250 yuan. Q: How many kilograms is the watermelon?
Question 7. In the darts competition, it is stipulated that each player gets 65,438+00 points, and each player misses the target and gets 6 points. Each player throws 10 times and scores * * * 152 points, in which player A scores more than player B 16 points. Q: How many times did each player win?
Question 8. There are 20 questions in the math contest. Every time he answers a question correctly, he gets 5 points. If he answers a wrong question, he will not only get no points, but also deduct 2 points backwards. Xiaoming got 86 points in this competition. Q: How many questions did he answer correctly?
1. solution: x sheets of 1 element and (28-x) sheets of 1 angle.
x+0. 1(28-x)=5.5
0.9x=2.7
x=3
28-x=25
A: There are three Zhang Yiyuan bills and 25 dimes.
2. Solution: Let 1 element have X, 2 yuan (x-2) and 5 yuan (52-2x).
x+2(x-2)+5(52-2x)= 1 16
x+2x-4+260- 10x = 1 16
7x= 140
x=20
x-2= 18
52-2x= 12
A: There are 20 1 yuan, 8 18 in 2 yuan and 2 12 in 5 yuan.
3. Solution: 7 yuan and 5 yuan have X pieces, and 3 yuan has (400-2x) pieces.
7x+5x+3(400-2x)= 1920
12x+ 1200-6x = 1920
6x=720
x= 120
400-2x= 160
A: 3 yuan has 160 and 7 yuan and 5 yuan have 120.
4. Answer: Total cargo: (3024-2520)÷2=252 (boxes)
There are x buses and (18-x) cars.
18x+ 12( 18-x)= 252
18x+2 16- 12x = 252
6x=36
x=6
18-x= 12
Answer: Bus No.6, 12.
5. Solution: Days = 1 12÷ 14=8 days.
It rained on day X.
20(8-x)+ 12x = 1 12
160-20x+ 12x = 1 12
8x=48
x=6
There are six rainy days.
6. Solution: Watermelon number: (290-250)÷0.05=800 kg.
There is a big watermelon x kg.
0.4x+0.3(800-x)=290
0.4x+240-0.3x=290
0. 1x=50
x=500
There are 500 kilograms of big watermelons.
7. Solution: A: (152+ 16)÷2=84.
B: 152-84=68 points.
Set armor x times
10x-6( 10-x)=84
10x-60+6x=84
16x= 144
x=9
Set b to y times.
10y-6( 10-y)=68
16y= 128
y=8
A: Nine times for A and eight times for B. ..
8. Answer: Suppose he answered question X correctly.
5x-2(20-x)=86
5x-40+2x=86
7x= 126
x= 18
A: He got it right 18. There is a distance of15km between the two posts A and B.. One day, the patrols of these two posts started from their respective posts at the same time and walked in opposite directions. A patrol walks 5.5km per hour, and B patrol walks 4.5km per hour. At the beginning of patrol at sentry B, a police dog they brought ran quickly towards patrol at sentry A, and returned immediately when they met team A until the two teams met. As we all know, the speed of police dogs is 20 kilometers per hour.