24 men working at 8 hours per day can do a piece of work in 15 days. I

1.	24 men working at 8 hours per day can do a piece of work in 15 days. In how many days can 20 men working at 9 hours per day do the same work?
Answer» M₁D₁H₁ = M₂D₂H₂ ∴ M₁ = 24 D₁ = 15 days H₁ = 8 hrs M₂ = 20 D₂ = ? H₂ = 9 hrs ⇒ 24 × 15 × 8 = 20 × x × 9 ⇒ x = (24 x 15 x 8)/(20 x 9) = 16 ∴ No. of days are required = 16 [ ∵ No. of men and working hours are in inverse]

24 men working at 8 hours per day can do a piece of work in 15 days. In how many days can 20 men working at 9 hours per day do the same work?

Answer»

M₁D₁H₁ = M₂D₂H₂

∴ M₁ = 24

D₁ = 15 days

H₁ = 8 hrs

M₂ = 20

D₂ = ?

H₂ = 9 hrs

⇒ 24 × 15 × 8 = 20 × x × 9

⇒ x = (24 x 15 x 8)/(20 x 9)

= 16

∴ No. of days are required = 16

[ ∵ No. of men and working hours are in inverse]