Question

Book club A charges $20 for membership and $2 per book rental. Book club B charges $10 for membership and $3 per book rental. For how many movie rentals will the cost be the same at both book clubs? What does that cost?

Answer 1

Given:

Book club A charges $20 for membership and $2 per book rental.

Book club B charges $10 for membership and $3 per book rental.

To find:

The number of books for which the cost be the same at both book clubs.

Solution:

Let x be the number of books.

Book club A charges $20 for membership and $2 per book rental. So, the total cost is

$C_1=20+2x$             ...(i)

Book club B charges $10 for membership and $3 per book rental. So, the total cost is

$C_2=10+3x$            ...(ii)

Equating (i) and (ii), we get

$10+3x=20+2x$

$3x-2x=20-10$

$x=10$

The total cost is

$C_1=20+2(10)$

$C_1=20+20$

$C_1=40$

Therefore, the total cost at both book clubs are same for 10 rental books and that cost is $40.