Multiple choice

If 12 boys or 15 girls can complete a work in 48 days, in how many days will 24 boys and 6 girls together complete twice that work?

  1. 30 days

  2. 20 days

  3. 36 days

  4. 40 days
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

12 boys = 15 girls, so 1 boy = 1.25 girls. 24 boys and 6 girls is equivalent to 30 + 6 = 36 girls. Since 15 girls take 48 days for 1 unit of work, 36 girls take (15/36) * 48 = 20 days for 1 unit, and 40 days for twice the work.

AI explanation

Given that 12 boys equal 15 girls in capacity, the ratio of a boy to a girl is 15 to 12, or 5 to 4. The total work is equivalent to 12 boys working for 48 days, giving a total requirement of 576 boy-days. We need to complete twice this amount, which is 1152 boy-days. The team of 24 boys and 6 girls has an equivalent capacity of 24 plus (6 times 4/5), which equals 28.8 boys. Dividing the 1152 boy-days of required work by the daily capacity of 28.8 boys gives exactly 40 days.

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