Mrs. Napholtz's Math Site
Percent Problems
A dealer pays $6000 for a car. The dealer wants to make a profit that is 25% of the selling price. For how much should the dealer sell the car?
He must sell (n) the car for $6000 plus 25% of the selling price (0.25n)
n = 6000 + 0.25n
0.75n = 6000
n = $8,000 Answer
Alex Stowe's house was reassessed at $126,000, up $6,000 from the last assessment. What was the percent increase?
Percent of increase = (New - Old)/Old
% incr. = (126,000 - 120,000)/120,000
% incr. = 6000 / 120000
% incr. = 6 / 120 = 1 / 20 = 5%
Answer: The percent increase was 5%
Suppose you paid $24 for a pair of shoes that were discounted 20%. What was the original price of the shoes?
If the shoes were discounted 20%, then you paid 80% of the original price.
24 is 80% of original.
24 = 0.80n
24/0.80 = n
n = 30
Answer: The original price was $30.00
Kevin bought a car for $12,000. A year later, it was worth $9,000. What was the percent decrease in value?
Percent decrease = (New - Old)/Old
Percent decrease = (9000 - 12000)/12000
Percent decrease = -3000/12000
Percent decrease = -1/4
Answer: The Percent Decrease was 25%.
NOTE: The "negative" sign indicates that the price decreased!