David is selling 1200 novels. He sold 75% of them at $12 each, 30% of the remainder at a discount of 25% and the rest at cost price. He made a profit of $2488. Find the cost price of a novel.

Price	$12	$9	Cost Price
Percent	75%	25%
		7.5%	17.5%
Number	900	90	Not needed
Amount collected	$10800	$810	Not needed

Number of novels sold at $12
= 75% x 1200
= ⁷⁵₁₀₀ x 1200
= 900

Price after 25% discount
= 75% x 12
= ⁷⁵₁₀₀ x 12
= $9

Remaining novels
= 1200 - 900
= 300

Number of novels sold at $9
= 30% x 300
= ³⁰₁₀₀ x 300
= 90

Number of novels sold at $12 or 25% discount
= 900 + 90
= 990

Total amount collected from the sale of 900 novels
= 900 x 12
= $10800

Total amount collected from the sale of the other 90 novels
= 90 x 9
= $810

Total amount collected from the sale of novels sold at $12 or 25% discount
= 10800 + 810
= $11610

Cost price of 990 novels
= 11610 - 2488
= $1980

Cost price of 1 novel
= 1980 ÷ 990
= $2

Answer(s): $2