Anew type of pump can drain a certain pool in 7 hours. an older pump can drain the pool in 13 hours. how long will it take both pumps working together to drain the pool?

Both the pumps together will drain the pool in 4.55 hours.

Step-by-step explanation:

Pool can be drained by a new pump in the duration = 7 hours

Older pump can drain the pool in the time = 13 hours

Per hour capacity of the new pump to drain the pool = part of the pool

Per hour capacity of the older pump = part of the pool

When both the pumps work together then part of the pool drained in one hour =

=

=

Since part of the pool is drained in the time = 1 hour,

therefore full pool will be drained in the duration =

=

= 4.55 hours