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 4.2 MB. Yesterday, the high-quality version was downloaded three times as often as the standard version. The total size downloaded for the two versions was 3427 MB. How many downloads of the standard version were there?

Answer 1

270

Explanation:

aleks answer

Answer 2

230

Explanation:

Let number of downloads of standard version be x,

and

number of downloads of high quality version be y

We can write 2 equations and solve simultaneously.

"the high-quality version was downloaded three times as often as the standard version.":

`y=3x`

"The size of the standard version is 2.3 megabytes (MB). The size of the high-quality version is 4.2 MB ... The total size downloaded for the two versions was 3427 MB":

`2.3x+4.2y=3427`

Now, plugging in equation 1 into equation 2, we can solve for x (hence standard version downloads number):

`2.3x+4.2y=3427\\2.3x+4.2(3x)=3427\\2.3x+12.6x=3427\\14.9x=3427\\x=230`

There were 230 downloads of the standard version