Correct Answer - Option 4 :
\(7\frac{9}{{13}}\)
Given:
10 men can finish a piece of work = 10 days
12 women can finish a piece of work = 10 days
Calculations:
1 man can complete a piece of work = 10 × 10
⇒ 100 days
1 woman can finish a piece of work = 12 × 10
⇒ 120 days
The ratio of number of days work done by man and women = 100 ∶ 120
⇒ 5 ∶ 6
1 woman =5/6 men
8 men and 6 women = 8 men + 6 × 5/6 men
⇒ 8 men + 5 men = 13 men
13 men can complete work in = 10 × 10/13
⇒ \(7{9 \over 13}\) days
∴ 8 men and 6 women can complete a work in \(7{9 \over 13}\) days.