Question

the campus bookshop sells exercise books and textbooks, where, the total cost of 10 exercise books and 2 textbooks is $1400.00. One also finds the total cost of 3 textbooks and 30 exercise books is $3000. Then determine the price of 1 exercise book?

Answer 1

Answer:

The price of 1 exercise book is $122.45.

Step-by-step explanation:

This question is solved using a system of equations.

I am going to say that:

x is the price of one exercise book.

y is the price of one textbook.

Total cost of 10 exercise books and 2 textbooks is $1400.00.

This means that:

$10x + 2y = 1400$

Since we want x:

$2y = 1400 - 10x$

$y = 700 - 5x$

One also finds the total cost of 3 textbooks and 30 exercise books is $3000.

This means that:

$3x + 30y = 3000$

Since $y = 700 - 5x$

$3x + 30(700 - 5x) = 3000$

$3x + 21000 - 150x = 3000$

$147x = 18000$

$x = \frac{18000}{147}$

$x = 122.45$

The price of 1 exercise book is $122.45.