a web music store offers two versions of a popular song.

Question

the size of the standard version is 2.3 (mb). the size of the high quality version is 4.2 MB. Yesterday, there were 960 downloads of the song, for a total download size of 2835 MB. how many downloads of the high quality version were there?

Answer 1

Let D₁ = number of 2.3 mb downloads

D₂ = number of 4.2 mb downloads

From the information given

D₁ + D₂ = 960

and 2.3D₁ + 4.2D₂ = 2835

Then D₂ = 960 - D₁ and 2.3D₁ + 4.2(960 - D₁) = 2835

From which you get 1.9D₁ = 1197

D₁ = 630 (number of 2.3 mb downloads)

Therefore, D₂ = 960 - 630 = 330 (number of 4.2 mb downloads)