Ref: Manhattan Prep GMAT Guide 1 ED 6, page 123.
AB
X CA
________
DEBC
Why does the solution choose different CA numbers to test the answer?
Thank you
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- KenY509
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- Sage Pearce-Higgins
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Re: Unknow Digits Problem
In my edition the problem states that "each letter stands for a different non-zero integer", so that C and A have to be different.
As for a strategy, the solution shown here applies a combination of elimination, and working backwards from the answer choices (both extremely useful approaches). Given the various constraints in the question, there are only 4 possible multiplications, meaning that it's pretty quick to list them all out and see which one works.
When you're using these books, I would strongly recommend trying to solve the problems before looking at the solution. I know how easy it is just to read through these books, but if you cover up the explanation and give yourself a few minutes to attempt the problem you'll get more out of your study time.
As for a strategy, the solution shown here applies a combination of elimination, and working backwards from the answer choices (both extremely useful approaches). Given the various constraints in the question, there are only 4 possible multiplications, meaning that it's pretty quick to list them all out and see which one works.
When you're using these books, I would strongly recommend trying to solve the problems before looking at the solution. I know how easy it is just to read through these books, but if you cover up the explanation and give yourself a few minutes to attempt the problem you'll get more out of your study time.
2 posts Page 1 of 1