Multiple choice

10 men can complete a work in 7 days. But 10 women need 14 days to complete the same work. How many days will 5 men and 10 women need to complete the work?

  1. 5

  2. 6

  3. 7

  4. 8

  5. 9
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

10 men in 7 days means 1 man does 1/70 of the work per day. 10 women in 14 days means 1 woman does 1/140 of the work per day. 5 men and 10 women do 5/70 + 10/140 = 1/14 + 1/14 = 2/14 = 1/7 of the work per day. They need 7 days to complete the work.

AI explanation

Let the total work be 140 units, making the efficiency of 10 men 20 units per day and the efficiency of 10 women 10 units per day. The efficiency of 5 men is 10 units per day, which when added to the 10 units per day from 10 women gives a combined efficiency of 20 units per day. The time required to finish the work is 140 units divided by 20 units per day, which equals 7 days.

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