Multiple choice

A can complete a work in 12 days and B can complete the same work in 6 days. If A works alone for 4 days and then B completes the remaining work, how many days does B take to finish it?

  1. 2 days

  2. 3 days

  3. 4 days

  4. 5 days
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A's rate = 1/12, B's rate = 1/6. A works for 4 days, doing 4/12 = 1/3 of the work. Remaining work = 2/3. B takes (2/3) / (1/6) = (2/3) * 6 = 4 days.

AI explanation

Using the one day work method, A's rate is 1/12 and B's rate is 1/6. A works alone for 4 days, completing 4 times 1/12, which equals 1/3 of the total work, leaving 2/3 of the work remaining. To find B's required time, divide the remaining 2/3 by B's daily rate of 1/6. The calculation (2/3) divided by (1/6) equals 4 days.

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