You know the drill by now. The prize this week will, once again, be beta access to the Math Guide, which is really coming along nicely, if I do say so myself. I kinda can’t believe it’s going to top 300 pages, but at this rate we’re definitely heading in that direction.

Anyway, to get a look at it now and come along for the ride while I finish it up, be the first to answer the following question correctly in the comments, or send me $5 using the link above.

A stereo equipment store owner notices that all his customers spend between $110 and $298, inclusive, in his store when they come in. For no discernible reason other than that I need a difficult math problem, he decides to express the range of dollar amounts his customers spend, s, in an inequality of the form |s – j| ≤ k, where j and k are constants. What is jk?

I’ll post the solution Monday. Good luck!UPDATE: Nice work, Serplet. Solution below.

Questions like this aren’t super common on the SAT, but when they appear they always follow the same pattern:

|variable – middle of range| < distance from middle to ends of range

In this case, the range is 110 < s < 298, so the middle of the range is (110 + 298)/2 = 204 , and the distance from the middle to the ends of the range is (298 – 110)/2 = 94.

So j = 204, and k = 94. Their product is 19176.

For more practice with this kind of question, go here.

Comments (5)

Leave a Reply