Question

A Web music store offers two versions of a popular song. The size of the standard version is 2.3 megabytes (MB). The size of the high-quality version is 4.8 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 4515 MB. How many downloads of the standard version were there?

Answer 1

Let x = download size of the standard version.

4515 - x = download size of high quality version.

High quality was downloaded 4 times more so 4 x 4.8 = 19.2 = downloads of high quality versions.

Set up a ratio:

2.3 / 19.2 = x / 4515-x

Cross multiply:

2.3(4515-x) = 19.2x

10384.50 -2.3x = 19.2x

Add 2.3x to both sides:

10384.50 = 21.5x

Divide both sides by 21.5:

X = 10384.50/21.5

X = 483

There were 483 downloads of the standard version.