A book normally cost $21.50. Today it was on sale for $15.05. What percentage discount was offered during the sale. ( Please explain, i'm desperate!)

30%

Step-by-step explanation:

Subtract the original cost from the on sale price.

21.50 - 15.05 = 6.45

Divide the savings by the original cost.

6.45/21.50 = .3

Multiply by 100

.3 * 100 = 30

30% percent

Step-by-step explanation:

21.50-15.05=6.45

21.50÷6.45=3.

3×100=30%

we times 100 because 1 equal 100%.So you need to do is just to multiply the number by 100 and add at the end symbol %

215.92 dollars is the answer