Question

A and B can do a piece of work in 12
days, B and C in 15 days, cand A in 20 days
How long would it take for c to do the
same work alone.​

Answer 1

Answer:

A + B = 15.

B + C = 8

then we have the value of A put it in first equation

20 + B = 12.

B = 12 - 20

B = -8

now put the value of B in 2 equation

-8 + C = 15.

C = 15 +8

C = 23