Question

There are 150 calories in a cup of whole milk and only 94 in a cup of skim milk. In switching to skim milk, find the percent decrease in number of calories.

Answer 1

 It decreased by 37.5%

Answer 2

We know that the percentage decrease is given by:

Percentage Decrease=$\frac{Original-Final}{Original}\times 100$

On our case the Original Value is 150 calories and the final value is 94 calories. Therefore, in switching to skim milk, the percent decrease in number of calories is given by:

Percentage Decrease=$\frac{Original-Final}{Original}\times 100=\frac{150-94}{150}\times 100=37.33$%

Thus the answer is 37.33%.