Will someone answer this for me please, I'd really appreciate it.

john is draining a pool he has two pumps but he can only use one at a time he know that the time a pump takes to drain the pool varies inversely with the power in watts of the pump his old pump is a 80 watt pump and it can drain the pool in 5 hours how long would the job take if he uses his new 100 watt pump

Tldr version: if it take 5 hours to pump a pool with an 80 watt pump how long will it take with a 100 watt pump

Please.