It takes an older pump twice as long to drain a certain pool as it does a newer pump. working together, it takes the two pumps 3 hours to drain the pool. how long will it take the newer pump to drain the pool working alone

Respuesta :

15+3=5t 5t=18 t=18/5=3.6 hours---time it takes newer pump to drain the pool CK 1/3.6 + 1/18=1/3 5/18+1/18=1/3 1/3=1/3