SAT Math Multiple Choice Question 39: Answer and Explanation
9. Of all the houses in a certain neighborhood, 80% have garages. Of those houses with garages, 60% have two-car garages. If there are 56 houses with garages that are not two-car garages, how many houses are there in the neighborhood?
- A. 93
- B. 117
- C. 156
- D. 175
Correct Answer: D
D Start by figuring out what percent of the houses do not have two-car garages. Since 60% of the houses with garages have two-car garages, 40% of the houses with garages do not have two-car garages. In other words, 40% of 80% of the houses do not have two-car garages. Translate that into math to get × = 0.32 or 32% of the houses. The problem tells us that 56 houses do not have two-car garages, which means 32% of the houses equals 56. Translating into math gives us × x = 56. Solve for x, and you'll get 175, which is (D).