Multiple choice

A and B can complete a work in 36 days and 48 days, respectively. They worked together for 8 days and then B left. In how many days will A alone complete the remaining work?

  1. 28 days

  2. 34 days

  3. 22 days

  4. 32 days

  5. 25 days
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A's rate = 1/36, B's rate = 1/48. Together = 1/36 + 1/48 = 7/144. In 8 days, they do 8 * 7/144 = 56/144 = 7/18. Remaining = 11/18. A takes (11/18) / (1/36) = 11 * 2 = 22 days.

AI explanation

Let the total work be the least common multiple of 36 and 48, which is 144 units. A's efficiency is 4 units per day and B's efficiency is 3 units per day. Working together for 8 days, they complete 56 units ((4 plus 3) multiplied by 8), leaving 88 units of work (144 minus 56). A alone completes the remaining 88 units at a rate of 4 units per day, which takes 22 days (88 divided by 4).

Keep practicing — related questions