A and B can do a job in 25 days and 18 days, respectively. A works alone for 4 days and leaves. The number of days required by B to complete the remaining job is:

Question

Question

This question was previously asked in

RRB NTPC Graduate Level CBT-I Official Paper (Held On: 06 Jun, 2025 Shift 1)

Answer 1

Given:

A can do the job in 25 days

B can do the job in 18 days

A works for 4 days and leaves

Calculation:

Assume total work = LCM of 25 and 18 = 450 units

A's rate = 450 ÷ 25 = 18 units/day

B's rate = 450 ÷ 18 = 25 units/day

⇒ Work done by A in 4 days = 4 × 18 = 72 units

⇒ Remaining work = 450 − 72 = 378 units

⇒ Time for B = 378 ÷ 25 = 15\(\frac{3}{25}\) days

∴ B will take 15\(\frac{3}{25}\) days to finish the job.