39) The cost of 1 book is 80 However, a dozen of the same books can be bought for 720 . How much is saved on each book when they are bought by the dozen? a. 20 b. 25 C. 35 d 240 1 point

To find out how much is saved on each book when they are bought by the dozen, we need to compare the cost of one book with the cost of one book when bought in a dozen.<br /><br />The cost of one book is $\$ 80$.<br /><br />When bought in a dozen, the total cost is $\$ 720$. To find the cost of one book when bought in a dozen, we divide the total cost by the number of books in a dozen:<br /><br />\[<br />\text{Cost of one book when bought in a dozen} = \frac{\$ 720}{12} = \$ 60<br />\]<br /><br />Now, we can find the savings per book by subtracting the cost of one book when bought in a dozen from the original cost of one book:<br /><br />\[<br />\text{Savings per book} = \$ 80 - \$ 60 = \$ 20<br />\]<br /><br />Therefore, the correct answer is:<br /><br />a. $\$ 20$