Answer:
Dorsey = 4.8 hours
Campbell = 24 hours
Step-by-step explanation:
It takes "x" hours for Dorsey
So, it will take 5 times more for Campbell, so
It takes "5x" hours for Campbell
Rate is inverse of time, so rates are:
Dorsey: 1/x
Campbell: 1/5x
We know Rate * Time = Work
When together, it takes 4 hours to finish a work, so we can write:
Solving for x, we get the time of Dorsey:
Dorsey takes 4.8 hours alone
Campbell takes 4.8 * 5 = 24 hours alone