Multiple choice

Adam is twice as efficient workman as Brain and together they finish a piece of work in 12 days. In how many days will Adam alone finish the work?

  1. 19

  2. 21

  3. 18

  4. 23
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let Brain's work rate be r, so Adam's rate is 2r. Together their rate is 3r = 1/12, giving Adam's rate as 1/18. Therefore, Adam alone completes the work in 18 days.

AI explanation

Using the efficiency method, let Brian's efficiency be 1 unit per day, making Adam's efficiency 2 units per day. Their combined efficiency is 3 units per day, so the total work is 3 multiplied by 12, which equals 36 units. Adam alone will take 36 units divided by his efficiency of 2, which equals 18 days.

Keep practicing — related questions