Question

8 girls take 16 days to finish stitching 20-bed sheets working 4 hours a day. How many hours in a day will 4 girls work in a day if they have to finish 25-bed sheets in 8 days?
1. 20
2. 24
3. 25
4. 21

Answer 1

Correct Answer - Option 1 : 20

Given:

Number of total girls = 8

Number of days = 16 days

Work = Stitching 20 bed sheets

Per day work = 4 hours

Formula used:

1.) MDH/W is constant.

2.) M₁ × D₁ × H₁/W₁ = M₂ × D₂ × H₂/W₂

Where,

M → The number of men

H → The number of hours

D → The number of days

W → The amount of work

Calculation:

Here, M₁ = 8, H₁ = 4, D₁ = 16 and W₁ = 20

Let the number of hours taken by 4 girls be h.

So, M₂ = 4, H₂ = h, D₂ = 8 and W₂ = 25

⇒ 8 × 4 × 16/20 = 4 × 8 × h/25

⇒ h = 20

∴ 4 girls need to work for 20 hours a day.