Luis is selling 700 non-fiction books. He sold 75% of them at $12 each, 40% of the remainder at a discount of 25% and the rest at cost price. He made a profit of $2117. Find the cost price of a non-fiction book.
| Price |
$12 |
$9 |
Cost Price |
| Percent |
75% |
25% |
| |
|
10% |
15% |
| Number |
525 |
70 |
Not needed |
| Amount collected |
$6300 |
$630 |
Not needed |
Number of non-fiction books sold at $12
= 75% x 700
=
75100 x 700
= 525
Price after 25% discount
= 75% x 12
=
75100 x 12
= $9
Remaining non-fiction books
= 700 - 525
= 175
Number of non-fiction books sold at $9
= 40% x 175
=
40100 x 175
= 70
Number of non-fiction books sold at $12 or 25% discount
= 525 + 70
= 595
Total amount collected from the sale of 525 non-fiction books
= 525 x 12
= $6300
Total amount collected from the sale of the other 70 non-fiction books
= 70 x 9
= $630
Total amount collected from the sale of non-fiction books sold at $12 or 25% discount
= 6300 + 630
= $6930
Cost price of 595 non-fiction books
= 6930 - 2117
= $2975
Cost price of 1 non-fiction book
= 2975 ÷ 595
= $5
Answer(s): $5
