1. There are two piles of coal. The first pile weighs two-thirds of a ton, and the second pile weighs one-third more than the first pile. How many tons does the second pile weigh? 2. It is planned to fold 40 paper cranes. Five eighths of them have been folded. How many more can be folded to complete the task?

1. There are two piles of coal. The first pile weighs two-thirds of a ton, and the second pile weighs one-third more than the first pile. How many tons does the second pile weigh? 2. It is planned to fold 40 paper cranes. Five eighths of them have been folded. How many more can be folded to complete the task?

1. 2 / 3 × 1 / 3 + 1 / 3 = 5 / 9 (ton)
2.40 × (1-5 / 8) = 15

According to the formula, two piles of coal, 8.1 tons in total, were transported to Sichuan disaster area. Three thirds of the coal was used in the first pile, and five thirds in the second pile

Let the first pile be XT and the second pile be YT
There are: 1 / 3x + 2 / 5Y = 5 / 6x (1)
x+y=8.1 (2)
The general score (1) is: 4Y = 5x, that is, X: y = 4:5
Substituting (2): x = 3.6T, y = 4.5t

Two new 8.1 tons were transported, the first - 3 / 2, the second - 5 / 3, and the remaining one was 6 / 1 less than the first

Suppose that each pile is x tons
X-2X/3+（8.1-X）*（1-3/5）=X-X/6
X/3+3.24-2X/5=5X/6
9X/10=3.24
X=3.6
The original first pile is 3.6 tons

There are two piles of coal. The weight of the first pile is 6 / 7 of that of the second pile. The first pile uses 9 tons and the second pile uses 8 tons. The remaining weight of the first pile is the same as that of the second pile
3 / 4, two piles of coal each weight

Set up the second pile of X tons
6/7x-9=3/4(x-8)
6/7x-9=3/4x-6
6/7x-3/4x=9-6
3/28x=3
x=28
The first batch was 28x6 / 7 = 24 tons