Question

8 cleaners can clean an office in 3 hours,if the block needs to be cleaned in 2 hours,how many cleaners will be needed?

Answer 1

12 cleaners

Explanation:

8 cleaner can clean in 3 hours = 1 office

1 cleaner can clean in 3 hours =
`(1)/(8)` part of job

1 cleaner can clean in 1 hours =
`(1)/(3 * 8)` part of job

Let the number of cleaner required to finish the job in 2 hours = x

hence

x cleaner can clean in 1 hours =
`(1 * x )/(24)` part of job

x cleaner can clean in 2 hours =
`(2 * x )/(24)` part of job

Hence

`(2 * x )/(24)=1`

`(2x)/(24)=1`

`2x=24`

`x=12`

Hence we need 12 men to complete the same job in 2 hours