Each minute, 1/7 of the tank is filled and 1/9 drained.
1/7 - 1/9 = 1/x
Once we find the common denominator, 63x, we don't need it anymore.
9x - 7x = 63
2x = 63
x = 31.5
It will take 31 minutes and 30 seconds to fill the tank.
Ellie Dean T.
asked 12/18/17
Get a free answer to a quick problem.
Most questions answered within 4 hours.
Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.