Question

a and b together can do a piece of work in 20 days b and c together can do it in 15 days , c and a can do it in 12 days ​

Answer 1

Step-by-step explanation:

a+b 1 day work = 1/12 -------> equation 1

b+c 1 day work= 1/15 ----------> equation 2

c+a 1 day work= 1/20 -------------> equation 3

by subtracting equation 1 and 2 we get

a-c = 1/60 --------------------> equation 4

now adding equation 3 and 4

we get A's one day work

a=1/30 ------------------------> equation 5

now putting value of equation 5 in equation 1 and 3

we can get value of C and B respectively 1/20 and 1/60

A's one day work + B's one day work + c's one day work = 1/10

if they work together it will take 10 days to complete them the whole work !