Mary purchases four book online. The book were the same price each, and the shipping fee was $7.25. If the total cost was $55.25, what was the price of each book?

The price per book that Mary purchased is $12

Step-by-step explanation:

Mary's total cost can be expressed as;

C = (p*n) + s

where;

C=total cost

p=price per unit of books

n=number of books purchased

s=shipping fee

In our case;

C=$55.25

p=unknown

n=4

s=$7.25

replacing;

55.25 = (4*p) + 7.25

4 p+7.25=55.25

4 p=55.25-7.25

4 p=48

p=48/4

p=12

The price per book that Mary purchased is $12