Question

Mr. Ramsey just finished bathing his kids, and now he is draining the tub. The tub contains 32 gallons of water and is draining at a rate of 3 gallons per minute. After 7 minutes, how many gallons are left in the tub?

Answer 1

The answer would be 11 gallons.

The tub starts with 32 gallons. Every minute it loses 3 gallons.

So after 1 minute it has lost 3 gallons. For example:
32-3= 29 Meaning that after 1 minute the tub has 29 gallons left.

Now you have to remember that the tub is draining for 7 minutes. So it is losing 3 gallons 7 times, because it loses 3 gallons each minute and there are 7 minutes.

We can use multiplication to find how many gallons the tub loses after 7 minutes. This sign “X” basically means “groups of”. We have 7 groups of 3, or
7 X 3

This is the same as saying we have 3, 7 times. Written like this:

3+3 +3 +3 +3 +3 +3 = 21

So after 7 minutes the tub has lost 21 gallons.

Now we take the original number of gallons and take away what was lost:

32-21=11

So there are 11 gallons left after 7 minutes.

Please let me know if you need any further explanation. Hope this helped.