15 persons have taken a job of digging a pond in 20 days. 5 persons have left after 10 days. Again after 5 days 5 more have left. How many days would be required to complete the job?

Question

Question

This question was previously asked in

RRC Group D Previous Paper 38 (Held On: 10 Oct 2018 Shift 2)

Answer 1

GIVEN:

Time taken by 15 people to dig the pond = 20 days

FORMULA USED:

Man – day formula

(m₁ × d₁ × h₁)/w₁ = (m₂ × d₂ × h₂)/w₂

Where m₁, m₂ is number of persons working

d₁, d₂ is number of days taken

h_1, h₂ is number of hours

w₁, w₂ is the units of work done

CALCULATION:

15 persons have taken a job of digging a pond in 20 days

Total work = 15 × 20 = 300 units

Work done by 15 men in 10 days = 15 × 10 = 150 units

Now,

5 men left the work

Work done by 10 men in 5 days = 10 × 5 = 50 units

Again 5 men left the work

Remaining work = 300 – (150 + 50) = 100 units

⇒ Remaining work will be done in 100/5 = 20 days

∴ Total number of days taken to complete the work = 10 + 5 + 20 = 35 days