To find: The time taken by Bob hose and Jim hose to fill the pool.
The time taken by Bob hose is 32.4 hours and time taken by Jim hose is 40.5 hours.
Given:
They both take 18 hours to fill the pool.
Bob’s hose takes 20% less time than Jim’s hose alone.
Calculation:
Let the time taken by Jim’s hose be x.
Time taken by Bob’s hose,
Tabulate the given information into the language of algebra.
In words  In Algebra 
Time taken by Jim’s  x hr 
Time taken by Bob’s  0.80x hr 
Work done by Jim’s hose 

Work done by Bob’s hose 

Work done by both hoses 

Model the equation for the above information.
Simplify the above equation for x,
The taken by Jim’s hose is 4.05 hours.
Time taken by Bob’s hose,
The time taken by Bob’s hose is 32.4 hours.
Thus, the time taken by Bob hose is 32.4 hours and time taken by Jim hose is 40.5 hours.