A total of 60 trees were planted by four people, one half of which was planted by a, one third by B and one fourth by C. how many trees were planted by D

A total of 60 trees were planted by four people, one half of which was planted by a, one third by B and one fourth by C. how many trees were planted by D

A is half of the total number of others, which means that a third of the total number is 20
B planted one third of the others, that is to say, 1 / 4 of the total, 15 trees
C 1 / 5 of the total, that is 12
The trees planted by Ding came out. 13
60/(1+1/2)=40 40*1/2=20
60/(1+1/3)=45 45*1/3=15
60/(1+1/4)=48 48*1/4=12
60-20-15-12=13

A, B, C and d have 60 lessons in tree planting. A is one of the other two, C is one of the other three, and B is one of the other three. How much is d worth?

The first one is the total tree
1/2÷（1+1/2）=1/3
The second one planted the total tree
1/4÷（1+1/4）=1/5
The results showed that: 1
1/3÷（1+1/3）=1/4
Ding planted the following trees:
1-1/3-1/4-1/5=13/60
D tree:
60 × 13 / 60 = 13 (trees)