A music store bought a CD set at a cost of $20. When the store sold the CD set, the percent markup was 40%. Find the selling price.

Selling price = $28

Step-by-step explanation:

Cost price = $20

Selling price = ?

Percent markup = 40%.

Percentage markup is the difference between a products selling price and cost as a percentage to the cost.

% mark up = (selling price - cost price) / (cost price) * 100

[ (Selling price - 20) / 20 ] * 100 = 40

40 / 100 = (selling price - 20) / 20

0.4 * 20 = selling price - 20

8 = selling price - 20

Selling price = $ (8 + 20)

Selling price = $28.

The selling price was $28

Answer: The selling price is $28

Step-by-step explanation: If the CD set was bought at the cost of $20 and sold at a selling price of $20 plus 40% (or 0.4), then we should start by calculating the value of 40% of the cost price, which would then be added to the cost price to arrive at the selling price.

The calculation is as follows;

Mark up = 20 x 0.4

Mark up = 8

Selling price = Cost price + Mark up

Selling price = 20 + 8

Selling price = 28

Therefore the selling price is $28