Multiple choice

12 boys, working 3 hours a day can complete a work in 20 days. How many hours a day must 18 boys work to complete the same work in 10 days?

  1. 4 hrs

  2. 18 hrs

  3. 10 hrs

  4. 12 hrs
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A Correct answer
Explanation

Using the formula M1*D1*H1 = M2*D2*H2, we have 12 * 20 * 3 = 18 * 10 * H2. This simplifies to 720 = 180 * H2, so H2 = 4.

AI explanation

Using the constant work formula (M1 * D1 * H1) = (M2 * D2 * H2), we can directly equate the scenarios. Substituting the values gives 12 boys * 20 days * 3 hours = 18 boys * 10 days * H2. This simplifies to 720 = 180 * H2. Solving for H2 gives 4 hours.

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