SAT Math Multiple Choice Practice Question 554: Answer and Explanation
11. If b is a positive number not equal to 1, which of the following must also be positive?
D. 2 – b
E. 2b – 1
Correct Answer: A
A Be sure to read the question carefully; the key here is must be positive. Let's try plugging in an easy number for b. If you make b = 2, then let's see which of the choices is positive. A becomes . B becomes , so you can eliminate it. C becomes . D becomes 0, so you can eliminate it, and E becomes 3. Now let's try making b = . In this case, A becomes . C becomes –1, so you eliminate it. E becomes 0; eliminate. That leaves you with A.