Final answer:
The original cost of the desk lamp with a 90% markup and a selling price of $22.95 is approximately $12.08. The amount of the markup is $10.87.
Step-by-step explanation:
Calculating the Original Cost and Markup of a Desk Lamp
To calculate the original cost of the desk lamp when the selling price is $22.95 and the markup is 90% based on the cost, we first need to understand what markup means. Markup is the percentage increase on the original cost of an item to reach its selling price. To find the original cost (C), we can use the formula:
Selling Price = Cost + (Cost × Markup Percentage)
By rearranging this formula to solve for the cost, we have:
Cost = Selling Price / (1 + Markup Percentage)
Next, we convert the markup percentage from a percentage to a decimal to use in the formula:
Markup Percentage as a decimal = 90% / 100 = 0.9
Now we can calculate the original cost (C) of the lamp:
Cost = $22.95 / (1 + 0.9) = $22.95 / 1.9 = $12.08
The original cost of the desk lamp is therefore approximately $12.08.
To find the amount of the markup in dollars, subtract the original cost from the selling price:
Markup Amount = Selling Price - Cost
Markup Amount = $22.95 - $12.08 = $10.87
The amount of the markup for the desk lamp is $10.87.