I was wondering if there is a typo in Problem Solving Answer Explanations for questions 148
. Please remember these questions are from OG 12
In Q 148: How did they get y
) + 10y) / (x +y)? Please note this is the third step in the answer.
In Q 230: The answer explanation said 2^17 instead of 2^-17. Is this right?
In Q148: That is not a typo. The numerator in the previous line is 10x + 20y; we can rewrite this as follows:
10x + 20y = 10x + 10y + 10y = 10(x + y) + 10y
That said, I find their solution to be quite awkward to this problem
In Q230: I don't see a typo here either. In the third line of the solved equation, they are dividing by 2^(-17). That's the same as dividing by 1/2^17, which is the same as multiplying by 2^17. I think that's the part of the solution you're referring to? Again, their solution is a bit awkward.
Nov 2011: After years of development, I am now making my advanced Quant books and high-level problem sets available for sale. Contact me at ianstewartgmat at gmail.com for details.
Private GMAT Tutor based in Toronto