Question

Jasmine can oil the lanes in a bowling alley in 10 hours. One day her friend joe helped her and it only took 4.44 hours. Find how long it would take joe to do it alone

Answer 1

Jasmine's rate is 1/10 alleys per hour

Together their rate is 1/4.44 alleys per hour.

Joe's rate must be

1/4.44 - 1/10 = 139/1110  alleys per hour

It would take Joe

1110/139 ≈ 7.99 hours to do an alley alone.

Let's call it 8 hours.