Question

A and B can do a piece in 24 days. B and C can do in 72 days and C and A can do it 72 days. what time can A alone do it ?

Answer 1

A+B take 24 days.
A+B one day work= 1/24
B+C take 72 days
B+C one day work = 1/72
C+A take 72 days
C+A one day work = 1/72
A+B+B+C+C+A's 1 day work= 1/24 + 1/72 + 1/72
2 (A+B+C) =( 3+1+1)/72
A+B+C= 5/72 × 1/2
A+B+C= 5/144
A+B+C's 1 day work - B+C's 1 day work= A 's 1 day work
5/144 - 1/72= A's 1 day work
3/144 = A's 1 day work
144/3 = 48 DAYS are taken by A to complete the work.☺