Warren is selling 700 textbooks. He sold 50% of them at $10 each, 20% of the remainder at a discount of 20% and the rest at cost price. He made a profit of $2297. Find the cost price of a textbook.

Price	$10	$8	Cost Price
Percent	50%	50%
		10%	40%
Number	350	70	Not needed
Amount collected	$3500	$560	Not needed

Number of textbooks sold at $10
= 50% x 700
= ⁵⁰₁₀₀ x 700
= 350

Price after 20% discount
= 80% x 10
= ⁸⁰₁₀₀ x 10
= $8

Remaining textbooks
= 700 - 350
= 350

Number of textbooks sold at $8
= 20% x 350
= ²⁰₁₀₀ x 350
= 70

Number of textbooks sold at $10 or 20% discount
= 350 + 70
= 420

Total amount collected from the sale of 350 textbooks
= 350 x 10
= $3500

Total amount collected from the sale of the other 70 textbooks
= 70 x 8
= $560

Total amount collected from the sale of textbooks sold at $10 or 20% discount
= 3500 + 560
= $4060

Cost price of 420 textbooks
= 4060 - 2297
= $2520

Cost price of 1 textbook
= 2520 ÷ 420
= $6

Answer(s): $6