We want to find Jamar's mistake and correct it. Let's calculate the selling price of the pair of skates ourselves first by using the percent equation.
part = percent * whole
We are given that the pair of skates costs $ 40 plus a 30 % markup. Let p represent the dollar amount of the markup.
p = 30 % * $ 40We need to write the percent as a decimal before we can solve the equation that we created. We can do this by ignoring the percent symbol and moving the decimal point two places to the left.
Therefore, 30 % is equal to 0.30, or 0.3.
p = 30 % * $ 40 [0.3em] ⇓ [0.3em]
p = 0.3 * $ 40
Now we can solve the equation for p. For simplicity, we will ignore the units for now.
We got that p= 12 is a solution to the equation, so the dollar amount of the markup is $ 12. Now we can calculate the selling price of the pair of skates.
$40 + $ 12 = $ 52
Now let's take a closer look at Jamar's solution.
We can see that Jamar subtracted the markup from $ 40, which is incorrect. He gave himself a 30 % discount instead! If he had added the markup to $ 40 like we did, he would have gotten that the selling price of the pair of skates is $ 52.
