araspai wrote:

A pet store holds cats and dogs. If the difference between the number of cats and the number of dogs is 13. What could be the ratio of Cats to dogs in the pet store?

A. 1:3

B. 1:4

C. 1:5

D. 2:5

E. 4:5

This question tests your understanding of the ratio scale vs actual values. If you recognise it, it takes you a few secs to get to your answer.

This concept has been discussed in detail here:

http://www.veritasprep.com/blog/2011/03 ... of-ratios/We all are aware that to convert ratio scale values to actual values, we multiply the ratio by the multiplier. We have also often used the sum of values concept for the "total" of actual values.

This question tests the same concept with the difference between values.

If the actual difference between values is 13, what could be the difference in values on the ratio scale? To get 13, the multiplier could have been 1 or 13. In case it was 1, then the difference between the values on ratio scale would be 13. If instead, the multiplier is 13, the difference between the values on the ratio scale would be 1.

Only option (E) satisfies this condition (difference between values on ratio scale is 1)

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Karishma

Veritas Prep GMAT Instructor

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