Question

A Web music store offers two versions of a popular song. The size of the standard version is 2.9 megabytes (MB). The size of the high-quality version is 4.7 MB. Yesterday, the high-quality version was downloaded four times as often as the standard version. The total size downloaded for the two versions was 6076 MB. How many downloads of the standard version were there?

Answer 1

Write the equations: $2.9s+4.7h=6076 \\ h= 4s$
Substitute for h: $2.9s+4.7(4s)=6076$
Solve for s:$2.9s+4.7(4s)=6076 \\ 2.9s+18.8s=6076 \\ 21.7s=6076 \\ s=280$
There were 280 downloads of the standard version. There were 1120 downloads of the high-quality version.