A can do a certain piece of work in 1.5 times the number of days in which B and C together can do it. If A and B together can do the same piece of work in 30 days and C alone can do it in 120 days, then how many days will B take to do this piece of work alone?

Question

Question

This question was previously asked in

SSC CGL 2023 Tier-I Official Paper (Held On: 24 Jul 2023 Shift 2)

Answer 1

Given:-

A can do a certain piece of work in 1.5 times the number of days in which B and C together can do it.

A and B together can do the same piece of work in 30 days

C alone can do it in 120 days

Concept:-

The ratio of efficiency is reciprocal of time.

Number of days required to complete a certain work = (Work to be completed/Work efficiency)

Calculation:-

A = 1.5 (B + C)

A/(B + C) = 3/2

A/(B + C)(efficiency) = 2/3

Total work be 120(LCM of 30 and 120)

Efficiency of A + B = 120/30 = 4 unit/day

Efficiency of C = 120/120 = 1 unit/day

Efficiency of B = 4 - 2 = 2 unit/day

Time taken by B to do this piece of work alone = 120/2

= 60 days.

The time taken by B to do this piece of work alone is 60 days.

Shortcut Trick

F8 Vinanti SSC 01.12.23 D2

The time taken by B to do this piece of work alone is 60 days.