A copy machine makes 24 copies per minute. How long does it take to make 138 copies?

Answer 1

To find the time it takes to make 138 copies, divide the total number of copies by the number of copies made per minute: 138 copies / 24 copies/minute = <<138/24=5.75>>5.75 minutes

Answer 2

A Web music store offers two versions of a popular song. The size of the standard version is 2.4 megabytes (MB). The size of the high-quality version is 4.7 MB. Yesterday, there were 1150 downloads of the song, for a total download size of 3910 MB. How many downloads of the high-quality version were there?

Answer 3

Let's assume that the number of downloads of the standard version is 'x' and the number of downloads of the high-quality version is 'y'.

Since the size of the standard version is 2.4 MB and there were 'x' downloads, the total download size for the standard version is 2.4x MB.

Similarly, since the size of the high-quality version is 4.7 MB and there were 'y' downloads, the total download size for the high-quality version is 4.7y MB.

According to the given information, the total download size is 3910 MB. Hence, we can form the equation:

2.4x + 4.7y = 3910 . (Equation 1)

Also, we know that the total number of downloads was 1150. Hence, we can form another equation:

x + y = 1150 . (Equation 2)

To solve this system of equations, we'll use a substitution method. Solving Equation 2 for x, we get:

x = 1150 - y

Now, substitute this value of x in Equation 1:

2.4(1150 - y) + 4.7y = 3910

Simplify and solve this equation for y:

2760 - 2.4y + 4.7y = 3910

2.3y = 3910 - 2760

2.3y = 1150

y = 1150 / 2.3

y = 500

Therefore, there were 500 downloads of the high-quality version.