Multiple choice

A works thrice as much as B. If A takes 60 days less than B to do a work then find the number of days it would take to complete the work if both work together?

  1. 22½days

  2. 22 days

  3. 23 days

  4. 24½ days

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

Let B take x days. A takes x-60 days. A works 3 times as fast, so x/(x-60) = 3. Solving: x = 3x - 180 → 2x = 180 → x = 90 (B's days), A = 30 days. Together: 1/30 + 1/90 = 4/90, so time = 90/4 = 22.5 days.