Question

a worker has a new pump and an old pump. the new pump can fill a tank in five hours and the old pump can fill the same tank in 7 hours write and solve an equation for the time it will take both pumps to fill one tank if the pumps are used together.
rate of old pump = tank/7
rate of new pump = tank/5
combined rate = tank/7 + tank/5
= (5tank + 7tank)/35 = 12tank/35

combined time = tank/(12tank/35)
= 35/12
= 2 11/12 hours = 2hours and 55 minutes
2 Hours 55minutes

Related Questions

Q work crew has two pumps, one new and one old. The new pump can fill a tank in 5 hours. The ols pum... . One pump can fill a tank with oil in 4 hours. A second pump can fill the same tank in 3 hours. If... One pump can fill a tank with oil in 4 hours. A second pump can fill the same tank in 3 hours. If bo... One pump can fill a tank with oil in 4 hours. A second pump can fill the same tank in 3 hours. If bo...