Question

Geoff and Max are college roommates. Geoff can clean their apartment in 2.5 hours and Max can clean their apartment in 3.25 hours. How long will it take Max and Geoff to clean their apartment together?

Answer 1

Answer: 1.41 hours

Explanation:

Geoff: 2.5 hours = 1 job

Max: 3.25 hours = 1 job

Together:
`(x)/(2.5) + (x)/(3.25) = 1 job`

⇒
`(3.25)(2.5)(x)/(2.5) + (3.25)(2.5)(x)/(3.25) = (3.25)(2.5)1`

⇒ 3.25x + 2.5x = 8.125

⇒ 5.75x = 8.125

÷5.75 ÷5.75

x = 1.413