Correct Answer - Option 2 : 55/2 days

**Given**

3 men and 4 female can do work in = 15 days

5 men and 3 female can do work in = 10 days

**Formula Used: **

Work = Time × Efficiency

**Calculation: **

⇒ let the efficiency of men and female be M and W

⇒ 3M + 4W = 15 , 5M + 3W = 10

⇒ LCM (15,10) = 30

⇒ Let total work = 30

⇒ efficiency of 3M + 4W = 2 ----(1)

⇒ similarly, 5M + 3W = 3 -----(2)

multiply the equation (1) by 3 and equation (2) by 4

⇒ 9M + 12W = 6 ------(1)

⇒ 20M + 12W = 12 -----(2)

⇒ From (3) and (4)

⇒ M = 6/11

⇒ total efficiency of 2 men = 12/11

⇒ No. of days taken by 2 men to complete the work = 30 × 11/12 = 55/2 days

⇒ No. of days taken by 2 men to complete the work is 55/2 days