GMAT Problem Solving Strategy: estimation

If you are looking at a problem solving question, and thinking about tackling it in a long, roundabout way, then you are probably looking at it wrong.  The questions are written in such a way that it seems like there is only an extremely complicated way of doing things, but in reality there is always a simpler way.   So, before you start going into that five minute calculation stop and think about if there is a quicker way to do things. 

Use what you are given, for example the test is multiple choice, so there is only a finite number of solutions to pick from.  If those choices are far enough away from each other, then you may only need to estimate.  Take, for instance, this problem:

What is 26% of 4/17 of 850?

  • A) 24
  • B) 54
  • C) 88
  • D) 146
  • E) 290

These answers are fairly spread apart, so you don’t have to do the entire calculation, which would be unnecessarily complicated and time consuming.   26% is a little over ¼ and 4/17 is a little under 4/16 or ¼, so you can just take ¼ of ¼ of 850, which is 1/16 of 850 or approximately 53.  There is no number that is anywhere near that except for B, so we know that is our answer.

Meet the Author

Eliza Chute

I was always just an average student, but with the right course prep I was able to score a 770 on my first try. I had to wade through a lot of material to find what was right for me, but luckily for you I've done all the research for you! See more on my GMAT courses page.

0 comments… add one

Leave a Comment