Multiple choice

A and B together complete a work in 20 days, B and C together complete the same work in 30 days, C and A together complete the same work in 24 days. In how many days can A, B and C together complete the same work?

  1. 8

  2. 16

  3. 12

  4. 15
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

2(A+B+C) = 1/20 + 1/30 + 1/24 = (6+4+5)/120 = 15/120 = 1/8. A+B+C = 1/16. So they take 16 days.

AI explanation

Let the one day work of A and B, B and C, and C and A be 1/20, 1/30, and 1/24, respectively. Adding these three values gives 2(A + B + C) = 1/20 + 1/30 + 1/24 = 15/120 = 1/8. The combined one day work of A, B, and C is half of this, which is 1/16. Therefore, A, B, and C together can complete the work in 16 days.

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