1. Liang Liang read a story book. He read 30% of the whole book on the first day, 40% of the whole book on the second day, and 398 pages in two days. How many pages are there in this book? 2. There are 5000 ducks and chickens in a farm. The ratio of ducks and chickens is 7:10. How many more chickens are raised than ducks?

1. Liang Liang read a story book. He read 30% of the whole book on the first day, 40% of the whole book on the second day, and 398 pages in two days. How many pages are there in this book? 2. There are 5000 ducks and chickens in a farm. The ratio of ducks and chickens is 7:10. How many more chickens are raised than ducks?

1. I read 30% + 40% in two days, so the whole book = 398 (30% + 40%)
2. Divide 5000 into 17 parts, 7 for ducks, 10 for chickens, 3 more for chickens than ducks
Therefore, there are 3 × (5000 △ 17) more chickens than ducks
Unfortunately, the results of these two questions are not integers, there are decimal points

A village plans to dig a 12 meter long canal. Four fifths of it is dug in the first day and three tenths of it is dug in the second day. How many meters are left?
2. It takes 10 minutes for a car to travel 15 kilometers and 9 minutes for a motorcycle to travel 15 kilometers. How many kilometers is the motorcycle more inert than the car per minute?
3. A road mender built 5000 meters in the first day, 4000 meters in the second day, and one third of a kilometer in the third day. How many kilometers did he build in the three days?
4. The school transported a pile of sand. It took three tons to build the wall, four fifths to build the sports ground, and three fifths to build the sports ground. How many tons were used? How many tons of sand were used?
5. The factory canteen used 1.5 tons of coal in the first quarter, four fifths less than the first quarter in the second quarter, and two fifths more than the second quarter in the third quarter?

Math problem formula, answer! Urgent!
A village plans to dig a 12 meter long canal. Four fifths of it is dug in the first day and three tenths of it is dug in the second day. How many meters are left?
12-（4/5+3/10）
=12-1.1
=10.9m
2. It takes 10 minutes for a car to travel 15 kilometers, and 9 minutes for a motorcycle to travel 15 kilometers. How many kilometers more does a motorcycle travel per minute than a car?
15÷9-15÷10
=5/3-3/2
=1 / 6 km
3. A road mender built 5000 meters in the first day, 4000 meters in the second day, and one third of a kilometer in the third day. How many kilometers did he build in the three days?
5/8+4/5+1/3
=1 and 17 / 40 + 1 / 3
=1 91 / 120 km
4. The school transported a pile of sand. It took three tons to build the wall, four fifths to build the sports ground, and three fifths to build the sports ground. How many tons were used? How many tons of sand were used?
3+4/5+3/5
=3 and 4 / 5 + 3 / 5
=4.4 tons
5. The factory canteen used 1.5 tons of coal in the first quarter, four fifths less than the first quarter in the second quarter, and two fifths more than the second quarter in the third quarter?
1.5-4/5+2/5
=0.7+0.4
=1.1 tons

1. There are 248 chickens and rabbits in the same cage. There are 52 fewer rabbits than chickens. How many chickens and rabbits are there?
The number of chickens and rabbits is 46 in total. If the number of chickens and rabbits is called, the number of feet will be 38. How many chickens and rabbits are there in total

Suppose there are x chickens and Y rabbits (1)2x+4y=248…………………… (2) From (2): x + 2Y = 124 (3) (3) + (1), have: 2Y - (- y) = 124-52, namely: 3Y = 72, the solution is: y = 24 (only) substitute (1), have: x-24 = 52, the solution is: x = 7