Harry is selling 1100 non-fiction books. He sold 50% of them at $10 each, 40% of the remainder at a discount of 40% and the rest at cost price. He made a profit of $2108. Find the cost price of a non-fiction book.
| Price |
$10 |
$6 |
Cost Price |
| Percent |
50% |
50% |
| |
|
20% |
30% |
| Number |
550 |
220 |
Not needed |
| Amount collected |
$5500 |
$1320 |
Not needed |
Number of non-fiction books sold at $10
= 50% x 1100
=
50100 x 1100
= 550
Price after 40% discount
= 60% x 10
=
60100 x 10
= $6
Remaining non-fiction books
= 1100 - 550
= 550
Number of non-fiction books sold at $6
= 40% x 550
=
40100 x 550
= 220
Number of non-fiction books sold at $10 or 40% discount
= 550 + 220
= 770
Total amount collected from the sale of 550 non-fiction books
= 550 x 10
= $5500
Total amount collected from the sale of the other 220 non-fiction books
= 220 x 6
= $1320
Total amount collected from the sale of non-fiction books sold at $10 or 40% discount
= 5500 + 1320
= $6820
Cost price of 770 non-fiction books
= 6820 - 2108
= $6930
Cost price of 1 non-fiction book
= 6930 ÷ 770
= $9
Answer(s): $9
