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 4.4
MB. Yesterday, there were 1070 downloads of the song, for a total download size of 4393 MB. How many downloads of the standard version were there?

Answer 1

s +h = 1070 ( total number of downloads)

Rewrite as s =1070 - h

2.9s + 4.4h = 4393 ( total download size)

Substitute:

2.9(1070-h) + 4.4h = 4393

Simplify:

3103 - 2.9h + 4.4h = 4393

Combine like terms:

3103 + 1.5h = 4393

Subtract 3103 from each side:

1.5h = 1290

Divide both sides by 1.5:

h = 1290 / 1.5

h = 860

Replace h with 860 in first equation to solve for s:

s + 860 = 1070

s = 1070 - 860

s = 210

There were 210 standard downloads and 860 high quality downloads