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SAT Prep Tip: Plug in Numbers (PIN)

SAT Prep, ACT Prep, College Admissions, High School, Math Problem

Plugging in Numbers (PIN) is a powerful SAT Prep Math strategy that we teach in our 2400 Expert courses. Use PIN on math questions that have abstract variables. By plugging in tangible numbers for abstract variables, we are able to solve problems much more easily. Today, I will illustrate how to use PIN on a College Board New SAT Math Question.

Question

Aaron is staying at a hotel that charges $99.95 per night plus tax for a room. A tax of 8% is applied to the room rate, and an additional onetime untaxed fee of $5.00 is charged by the hotel. Which of the following represents Aaron’s total charge, in dollars, for staying x nights?

Select Answer

(A) (99.5 + .08x) + 5
(B) 1.08(99.95x) + 5
(C) 1.08(99.95x + 5)
(D) 1.08(99.95 + 5)x

Solution

Let’s imagine that Aaron hotel stays for 2 nights. Therefore, x = 2. If Aaron stays for 2 nights, he would be charged ($99.95 x 2) + .08($99.95 x 2) + $5 = $220.89.

The only answer choice that comes up with $220.89 when we plug in x = 2 is B. Notice how we were able to solve this problem using no algebra at all. Of course, you could solve this using traditional high school algebra. But if you’re like me and prefer to be safe under the pressure of the SAT, plug in numbers!



Shaan Patel

Shaan Patel is the founder of Prep Expert Test Preparation (formerly 2400 Expert), a #1 bestselling SAT prep author, an MD/MBA student at Yale and USC, and winner of an investment deal with billionaire Mark Cuban on ABC's Shark Tank. He raised his own SAT score from average to perfect and teaches students his methods in an online SAT prep class.