A and B can do a piece of work in 28 days; B and C can do the same work in 18 days and A, B and C together can do it in 16 days. The time required (in days) to finish the work by A and C is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e.
A + B = 1/28
B + C = 1/18
A + B + C = 1/16
C = 1/16 − 1/28 = 3/112
B = 1/18 − 3/112 = 29/1008
A = 1/28 − 29/1008 = 7/1008
A + C = 7/1008 + 3/112 = 34/1008 = 17/504
Time = 1 / (A + C) = 504/17 = 29