288 MCGRAW-HILL’S SAT
Concept Review 5: Percents
- Complete the translation key:
- Write the formula for “percent change”:
- To increase a quantity by 30%, multiply it by 4. To decrease a quantity by 19%, multiply it by
- To increase a quantity by 120%, multiply it by 6. To decrease a quantity by 120%, multiply it by
Translate the following word problems and solve them.
- 5 is what percent of 26? Translation: ____ Solution: __
- 35% of what number is 28? Translation: ____ Solution: __
- 60 is 15% of what number? Translation: ____ Solution: __
- What percent is 35 of 20? Translation: ____ Solution: __
- What percent greater than 1,200 is 1,500? 11. ___
- If the price of a sweater is marked down from $80 to $68, what is the percent markdown? 12. ___
- The population of a city increases from 32,000 to 44,800. What is the percent increase? 13. ___
- What number is 30% greater than 20? 14. ___
- Increasing a number by 20%, then decreasing the new number by 20%, is the same as multiplying the orig-
inal by _____. - Why don’t the changes in problem 15 “cancel out”?
__________________________________________________________________________________________________- If the sides of a square are decreased by 5%, by what percent is the area of the 17. ___
square decreased? - 28% of 50 is the same as percent of , which equals _____.
- 48% of 25 is the same as percent of , which equals _____.
Word(s) in problem Symbol in equation
what, what number, how much
of
=
percent