Answer:
20
Step-by-step explanation:
Knowing that it is a 30-gallon bathtub.
And it fills at a rate of 3 gallons per minute.
But also drains 1.5 gallons per minute.
So this is for the first minute.
3 - 1.5 = 1.5
So there will be 1.5 gallons of water in the tub after the first minute.
Now do,
30 ÷ 1.5 = 20
It will take 20 full minutes for the bathtub to fill up.