Math help for pre algebra

There are 3 cups of water wasted every 24hrs.

How much is wasted in 1 week.

First we know that there are 24hrs in every day and 7 days in every week.

So there are 3 cups of water wasted every day(every 24hrs).

To find out how many cups of water are wasted in a week you would do: 3 cups * 7 days since there are 7 days in a week

3*7 = 21 cups of water wasted in a week.