Every student would like to find a “pure” solution to every problem. However, as SAT math questions get harder, it becomes virtually impossible to find this pure mathematical solution. If you can’t solve the problem outright, what should you do? Train yourself to try the choices.
Consider this problem:
A calculator company finds that 2% of all its calculators are defective. In a certain shipment, 16 defective calculators were found. How many calculators were in this shipment?
(A) .32 (B) 8 (C) 80 (D) 800 (E) 8000
If you can’t solve this directly, look at the choices. SAT choices are always arranged in order, usually ascending from left to right. A good strategy is to try choice C first, since it is the “middle-sized” choice. Try .02 * 80 = 1.6. This tells you that your choice was too small. Therefore, next try choice D and do .02 * 800 giving you exactly 16 proving choice D was right. Whenever you defeat an SAT question with a strategy like trying the choices, you might in the back of your mind wonder what the pure solution was (although, you got the same one point for bubbling in choice D). Here, one method of solution would have been to write and solve the equation .02x=16 and division by .02 gives x=800.
Tags: SAT Math, SAT Prep, SAT Preparation, SAT Test
Marty Rafson wrote the ESC math curriculum and has been an SAT math teacher, tutor, and curriculum developer for 30 years. He has been a high school math teacher for 36 years and a math department chairman for 25 years. He was also an adjunct professor at City College of New York School of Education.
