2014-08-27 09:00:18

1,440/(b + 2) < 144

If b is a positive number, then the inequality above is equivalent to which of the following?

(A) b < 8
(B) b > 8
(C) b < 10
(D) b > 10
(E) b > 144

The correct answer is B
Explanation: Inequalities can be solved in the same way that equations can: by doing the same operation on both sides of the inequality. To simplify this one, start by multiplying both sides by b + 2 to get rid of the division. The result is 1440 < 144(b + 2). Now, divide both sides by 144 to isolate the b + 2, leaving 1440/144 < b + 2, or 10 < b + 2. Finally, subtract 2 from both sides to isolate b, leaving 8 < b. This is equivalent to b > 8, making choice B correct.