Multiple choice

A and B can do a piece of work in 6 days and A alone can do it in 9 days. The time taken by B alone to do the work is. A और B किसी कार्य को 6 दिन में पूरा कर सकते हैं यदि A अकेला उसे 9 दिन में कर सकता है, तो B को उसे करने में अकेले कितना समय लगेगा?

  1. 18days/

  2. 20 days/दिन

  3. 22 days /दिन

  4. 24 days/दिन

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

A and B together: 1/6 work per day. A alone: 1/9 work per day. B's rate = Combined rate - A's rate = 1/6 - 1/9 = (3-2)/18 = 1/18 work per day. Therefore, B alone takes 18 days. The distractor 24 days would result from incorrectly adding the individual rates (1/6 + 1/9) instead of finding the difference.