Multiple choice

A has done 1/3rd of work in 30 days, B complete the rest of job in 90 days. In how many days can they together do the job?

  1. 34 days

  2. 32 days

  3. 54 days

  4. 52 days

  5. None of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A completes 1/3 of work in 30 days, so A's full work time = 30 × 3 = 90 days, rate = 1/90 per day. B completes remaining 2/3 work in 90 days, so B's full work time = 90 × 3/2 = 135 days, rate = 1/135 per day. Combined rate = 1/90 + 1/135 = 3/270 + 2/270 = 5/270 = 1/54. Together they complete the work in 54 days.