You are a compliance officer at an industrial plant. Each year, federal regulations require you to collect a 1-quart bottle of storm water runoff every 20 minutes for 3 hours. How many 1.quart bottles will you need?
A.7
В.9
С.17
D.25
E.60

This law is sometimes called the grouping property. as you can see, regardless of how the numbers are grouped, the answer is still 13. the associative law of multiplication is similar to the same law for addition. it says that no matter how you group numbers you are multiplying together, you will get the same answer.