10 men can complete a work in 12 days, and 10 women can complete the same work in 6 days. How many days will it take to complete the work if they work together?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 4 days.
1 man’s rate = 1/(10 × 12) = 1/120
1 woman’s rate = 1/(10 × 6) = 1/60
Combined rate (10 men + 10 women) = 10(1/120) + 10(1/60) = 1/12 + 1/6 = 1/4
Time to complete work = 1/(1/4) = 4 days