SAT Math Problem!

Test Preparation
1

<p>this is on page 420 of the PR book...</p>

<p>The recipe for a pie recommends that the pie be baked for at least 50 minutes, but not more than 60 minutes. If b is the number of minutes a pie, baked within the recommended time, is baked, which of the following represents all possible values of b? </p>

<p>A) l b-55 l =5
B) l b+55 l < 5
C) l b+55 l > 5
D) l b-55 l < 5
E) l b-55 l > 5 </p>

<p>According to the book, the answer is D, however I think it's C. When you plug in 60 for choice D, you get 5 which is not greater than 5, however C is true for all values. Is the book correct, and if so, why?</p>

2

<p>You can assume b=60 for choices C and D, but C does not give the complete set. For example, if b=0, 55 > 5, true, but b cannot equal 0. Here is the actual solution:</p>

<p>We know that 50 < b < 60. Subtract 55 from everything to obtain -5 < b-55 < 5. Every value from -5 to 5 has an absolute value less than 5, so we can say that |b-55| < 5, answer choice D.</p>

<p>Technically the answer should be |b-55| <= 5, because b=50 and b=60 are allowed.</p>

3

<p>ok, thank you!!</p>