Question

A CD makes 58 1/2 revolutions in 3/4 min.

Answer 1

The most important thing in this problem is understanding and then dividing the given units properly. The first thing that is given is that the CD makes 58 1/2 revolutions in 3/4 minutes. We have to first simplify the number of revolutions made by the CD. This will make the problem in hand very easy.
Number of revolutions made by the CD = 58 1/2
                                                               = 117/2
Then
The unit rate = (117/2)/(3/4)
                     = (117 * 4)/(2 * 3)
                     = (117 * 2)/3
                     = 39 * 2
                     78
So the unit rate is 78 revolutions per minute.

Answer 2

78 revolutions per minute 58.5 I divided it by 3 to get 19.5 Then multiplied 19.5 by 4 to get the amount of rotations in a minute