Answer:
48 minutes
Step-by-step explanation:
The rate of filling from both pipes is the sum of the rates in units of tanks per hour. We want the time for 2/3 of a tank.
<h3>Sum of rates</h3>
The sum of the filling rates is ...
rate A + rate B = (1/3) tank/hour + (1/2) tank/hour = 5/6 tank/hour
<h3>Fill time</h3>
The time to fill a tank or part thereof will be the number of tanks divided by the rate in tanks per hour:
time = (2/3 tank)/(5/6 tank/hour) = ((4/6)/(5/6)) hour = 4/5 hour
There are 60 minutes in an hour, so the fill time is ...
(4/5 hour)×(60 min/hour) = 48 min
It will take 48 minutes for both pipes to fill 2/3 of the tank.
