Question

A car wash has two employees on duty.

Employee I can finish washing a car in 30 minutes.
Employee 2 can finish washing a car in 20 minutes.
.
How long will it take the tiro employees to wash a car together?

Answer 1

60 minutes

Explanation:

Given that Employee I can finish washing a car in 30 minutes. and

employee 2 can finish washing a car in 20 minutes.

Assuming that both will wath the car together after n minutes.

So, n must be the integral multiple of 30 as well as 20.

For niminum value of n, n must be the lowest common factor of 30 and 20.

`\Rightarrow n = LCM(30,20) \\\\\Rightarrow n = 60.`

Hence, after 60 minutes, they will wash a care togethre.