Acomputer printer can print a 840-word document in 20 seconds. at this rate, how many seconds are required to print a document that contains 930 words?

930w(20s/840w)=155s/7

155s/7≈22.14 seconds (to nearest hundredth of a second)

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.