Question

39 persons can repair a road in 12 days, working 5 hours a day. In how many days will 30 persons, of same efficiency working 6 hours a day, complete the work ?
1. 10
2. 13
3. 14
4. 15

Answer 1

Correct Answer - Option 2 : 13

Given :

M1 = 39 person , M2 = 30 persons

D1 = 12 days , D2 = ?

H1 = 5 hours , H 2 = 6 hours 

Formula used :

M₁ × D₁ × H₁ / work₁   = M₂ × D₂ × H 2 / work₂

Calculation : 

Substituting the values in the formula

39 x 5 x 12  = 30 ×  6 ×  days

⇒ 2340 = 180 × days 

⇒ days = 2340 / 180 = 13 

 ∴ 30 persons will complete the work in 13 days.