Since the boundary values are squares of 10 and 11 and the equation is just x-20 less than x^2, I started plugging in numbers from 10 onwards and only 12 satisfies.

Other easier way was in the original equation start pugging in values starting starting from 10.

100<(x-5)(x+4)<121

If there is a better or easier way please let us know..

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired. If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links:

Quantitative |

Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.