Percent Increase Percent Decrease Problems

There are two ways to do these problems. Using the proportion: Using direct translation. I will solve each problem both ways – use the method that makes the most sense to you.

Holly bought a $90 sweater on sale for $15. What was the percent of the mark-down? Using the proportion: Cross-multiply Divide

Holly bought a $90 sweater on sale for $15. What was the percent of the mark-down? Direct translation: Original – original ( percent ) = new price 90 – 90p = 15 – 90p = 15 – 90 – 90p = – 75 p = 83.3%

Mrs. Smith bought a sweater on sale for $15. She sold it in eBay for $90. What was the percent of the mark-up? Using the proportion: Cross-multiply Divide

Mrs. Smith bought a sweater on sale for $15. She sold it in eBay for $90. What was the percent of the mark-up? Direct translation: Original + original ( percent ) = new price p = p = 90 – p = 75 p = 5.00 = 500% When you put the % on, you need to roll the decimal 2 places to the right.

Mrs. Smith bought a sweater on sale for $15. She marked it up 400% to sell in her online store. What was the new price? Using the proportion: x must go first since new price is bigger. Cross-multiply Divide

Mrs. Smith bought a sweater on sale for $15. She marked it up 400% to sell in her online store. What was the new price? Direct translation: Original + original ( percent ) = new price When you take the % off, you need to roll the decimal 2 places to the left. 400% = ( 4 ) = x = x 75 = x She is selling the sweater for $75.00

This year, Ming got a 10% raise. She is now making 80,000 a year. What was her salary last year? Using the proportion: must go first since new pay is bigger. Cross-multiply Divide

This year, Ming got a 10% raise. She is now making 80,000 a year. What was her salary last year? Direct translation: Original + percent ( original ) = new price When you take the % off, you need to roll the decimal 2 places to the left. 10% =.10 x +.10x = 80, x +.10x = 80, x = 80,000 x = 72,727.27

Percent Increase and Decrease Problems Can be solved using the proportion When you subtract put the larger number first The original always goes on the bottom Can be solved by direct translation If it is a mark-up or an increase, use + If it is a mark-down or a decrease, use –