
Charlotte C. answered 02/17/15
Tutor
5.0
(533)
Certificated Teacher, BA in Special Education, MA in ESOL
First find the dollar amount of increase by subtracting the purchase price from the selling price: $13.50 - $4.50. Next, determine what percentage of the original purchase price is that amount?
Here's an example: the store buys apples at $1.00 and sells them for $1.80. The difference is 80 cents. What percentage of the original $1 is that? It's 80/100 which is 80%. Remember with percentages you first put the numbers as a fraction, then divide the bottom number into the top number! Make sure you put the difference on top and the OLD price at the bottom, in order to find the percentage of mark-up. Have fun!!