MGMAT Word Problems - Integer Constraints

[paty.mogollon]

Hi,

On the MGMAT Word Problems book, page 19, it is presented a Data Sufficiency problem of ereases ($0.23 each) and pencils ($0.11 each).

The answer explain very good:

... it may be the case that there is only one way for a combination of pencils and erases to cost $1.7.

But I think that it is missing the explanation of how to identify if there is only one way for that combination.

If we had erases ($0.6 each) and pencils ($0.3 each), with a total cost of $1.5, we couldn't solve the question as explained. On this case, we would consider 1 erase and 2 pencils, so choose the letter B as answer. But it is wrong: 2 erases and 1 pencil can also be a result.

What is the rule?

I have the MGMAT 5th Edition.

Thanks,
Patricia

[StaceyKoprince]

Please make sure to read the forum guidelines before posting.

This folder is only for general strategy questions, not content or specific test problems. Check out the content / problem folders and post in the relevant folder depending upon the source of the problem you want to post (and make sure to follow the rules about banned sources). If you are a course student, you can also ask about other problems or issues before or after class or during section.

The question you've asked goes in the MGMAT quant non-CAT folder.

I'll answer you this time but please post in the appropriate folder in future!

Yes, that is exactly the trap - that's why you have to check the possibilities until you determine that there is just one answer (or that there is more than one). You know that there isn't just one answer if you find two combinations that work.