Question

210 men working 12 hours a day can finish a job in 18 days. How many men are required to finish the job in 20 days working 14 hours a day?

Answer 1

Let the required number of men be x.

More working hours ⇒ less men required.

∴ It is inverse proportion.

∴ Multiplying factor is 12/14

Also more number of days ⇒ less men

∴ It is an inverse proportion.

∴ Multiplying factor is 18/20

∴ x = 210 × 12/14 × 18/20 = 162 men

162 men are required.