Answer:
Bathtub currently has 45 gallons of water.
It drains 7 gallons every three minutes.
How much gallons will it have after 5 minutes.
First, find how much it drains in one minute and multiply it by 5.
7 gallons per 3 minutes.
So 7/3 = 2.3333 or roughly 2 gallons per minute.
How many gallons will it have after 5 minutes of draining.
2*5 = 10 litres will have been drained.
So, 45 - 10 = 35 gallons of water would remain after 5 minutes of draining.