Multiple choice

10 men can complete a piece of work in 7 days, while 10 girls take 14 days to complete the same work. Approximately how many days will 8 men and 10 girls together take to complete the work?

  1. 5.40 days

  2. 3.68 days

  3. 7 days

  4. 12 days

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

1 man's work per day = 1/70. 1 girl's work per day = 1/140. 8 men + 10 girls = 8/70 + 10/140 = 16/140 + 10/140 = 26/140 = 13/70. Time = 70/13 = 5.38 days, which is approximately 5.40.

AI explanation

Let the total work be the least common multiple of 7 and 14, which is 14 units. Since 10 men complete it in 7 days, 1 man does 1/5 unit per day, and since 10 girls complete it in 14 days, 1 girl does 1/10 unit per day. The combined daily work of 8 men and 10 girls is 8/5 + 1, which equals 13/5 units. Dividing the total work of 14 units by their daily capacity of 13/5 gives 70/13 days, which is approximately 5.38 days. Since the exact calculation gives 5.38 days, the closest provided option is 5.40 days.

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