1. A car travels for the first 3 hours 170km, and travels for 250km for the last 4 hours. How many kilometers does this car average per hour?

(1) (170+250) ÷ (4+3) = 60 (km/h)

2. When an engineering team builds a highway, it needs to build1.25km every day for the first four days and 6.7km in the last five days. How many kilometers will be built on average every day?

(2) (4×1.25+6.7) ÷ (4+5) =1.3 (km/day)

3. A winery produces 24,000 tons of cooking wine in the first half of the year and 6,000 tons of cooking wine every month in the second half. This year, tens of thousands of tons of cooking wine are produced on average every month.

(3) (2.4+0.6× 6) ÷ 12 = 0.5 (ten thousand tons/month)

There are two garden teams in the botanical garden. One team has workers 14, and can plant 1 104 trees every day. The second team has workers 16, with an average of 8 1 tree per person per day. How many trees do each of these two teams plant every day?

(4) (16× 81+1104) ÷ (16+14) = 80 (tree/person)

There is a math exam in Class One, Grade Five. There are 9 people in the first group, with an average score of 90; there are 9 people in the second group 10, with an average score of 89.5; there are 9 people in the third group 10, with an average score of 92.2; and there are 9 people in the fourth group with an average score of 86. What is the average score of the students in this class?

5] (9× 90+10× 89.5+00× 92.2+9× 86) ÷ (9+10+00+9) = 89.5 (min/person)

6. A construction site transports cement by car. The first shipment 12 cars, each with 4.5 tons, and the second shipment with 45 tons. This cement was used up in 30 days. How many tons of cement does this site use on average every day?

[6] (12× 4.5+45) ÷ 30 = 3.3 (ton/day)

7.A train from City A to City B traveled at 80km/h for 6 hours, at 90km/h for 7 hours and at 1 10 km/h for 3 hours. Find the average speed of this train.

Once (80× 6+90× 7+110× 3) ÷ (6+7+3) = 90 (km/h).

8. a car delivers goods from place a to place B. It takes six hours to drive there, at a speed of 46 kilometers per hour, and 5.5 hours to come back. What is the average speed of this car to and from the two places?

Equal to (46× 6× 2) ÷ (6+5.5) = 48 (km/h)

9. A washing machine factory will produce 1 0,400 washing machines, with an average of 80 washing machines per day in the first five days, and the rest will be completed within 10 days. How many units will be produced on average every day in recent 10 days?

Taxation (1400-5× 80) ÷10 =100 (unit/day)

10. A steel mill has an average of 0.10.6 million tons per day in the first three days and 0.10.95 million tons per day in the last four days. How many tens of thousands of tons a day this week?

(10) (0.16 * 3+0.195 * 4)/(3+4) = 0.180,000 tons.

1 1. Sharla Cheung read an extra-curricular book. He read 25 pages every day for the first 6 days, and then read 15 pages every day. Four days later, he just finished watching it. How many pages are there in this book?

⑾ 6× 25+(25+15 )× 4 = 310 (page 1)

12. Wang Hua got 88 points in Chinese and 95 points in math. How many points in English can make the average score of three subjects reach 92?

⑿92×3-(88+95)=93 (points)

13. A train goes uphill for 3 hours, with an average speed of 80 kilometers per hour, and downhill for 2 hours10 kilometers. Find the average speed of this train.

(80*3+2 10)/(3+2)=90

14. It took someone six hours to go from A to B, 84 kilometers away, because it took another eight hours to come back against the wind. Ask someone the average speed of going back and forth between A and B.

( 14)84×2÷(6+8)= 12

Application problem of finding area

1. There is a parallelogram plot with a bottom of 36 meters and a height of 25 meters. * * * Harvest rapeseed 135 kg. How many Jin of rapeseed is harvested per square meter on average?

135/(36*25)=0. 15

There is a room, which is 4.2 meters long and 3 meters wide. How many square floor tiles with a length of 30 cm are needed in this room?

30cm = 0.3m 4.2 * 3/(0.3 * 0.3)= 140

3. Triangle paddy field with bottom100m and height of 80m. How many seedlings can be planted in this paddy field if each seedling cluster covers an area of 0.02 square meters?

100*80/2/0.02=200000

The fish pond is trapezoidal in shape. Its upper bottom is 2 1 meter long, its lower bottom is 45 meters long and covers an area of 759 square meters. What is its height?

759*2/(2 1+45)=23

5. A pile of steel pipes is piled into a trapezoid, with the top layer 12, with one layer difference between every two adjacent layers and * * * 9 layers. How many steel pipes are there in this pile?

The bottom * * * has 12+9- 1=20.

There are (12+20)*9/2= 144 steel pipes in this pile.

6. The trapezoid has an area of 960 square centimeters, a height of 16 centimeters, an upper bottom of 48 centimeters, and a lower bottom of how many centimeters?

960*2/ 16-48=72