According to the meaning of the question:1/3 * (x+12.5) = 3/4 * X.
The solution is x= 10.
Therefore, the distance between a and b is:
X+(x+12.5) = 32.5km.
2. solution: let the total amount of this barrel of oil be x kilograms;
Then x-1/5 * x-(1/5 * x-4) = 52.
The solution is x=80.
So the oil sold for the first time is
1/5*x= 16 (kg)
3. Solution: The total amount of the project can be regarded as "1", so the work efficiency of A is 1/20.
B's work efficiency is 1/30.
Let the rest days of B be X, then there are
( 16-3)* 1/20+( 16-x)* 1/30 = 1
The solution is x=5.5.
That is, B rested for 5.5 days.
There are peach, pear and citrus trees in the orchard. The number of peach trees accounts for 20%, and the ratio of the number of pear trees to the sum of the other two trees is 1: 3. There are 132 strains of citrus. How many peach trees and pear trees are there?
Solution: If the total number is X, it is 20/ 100*x for peach trees and 1/4 * x for pear trees.
There are 20/100 * x+1/4 * x+132 = x.
The solution is x=240.
So there are 20/ 100*x=48 peach trees.
There are 1/4*x=60 pear trees.
If we solve this problem in the ordinary way:
Solution: Peach trees account for 20/ 100 of the total, pear trees account for 1/4 of the total, and dried tangerine peel accounts for the total.
1-20/ 100- 1/4= 1 1/20
Then the total number is132/(11/20) = 240 trees.
So the number of peach trees is 20/ 100*240=48.
The number of pear trees is 1/4*240=60.