Question of the Week: Geometric Solids

GRE prep

Don't Be Intimidated By Numeric Entry!

Check out the Question of the Week:

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Attempt the question; then read the explanation below.

 Sometimes It's Fastest to Solve Directly

When the GRE introduced Numeric Entry and Multiple Choice–Select One or More questions in 2011, I was concerned that many of the approaches to the GRE that we had developed would no longer be applicable to the new test format. Fortunately, I was wrong! In fact, GRE Numeric Entry problems sometimes present some of the clearest opportunities for direct math solutions. These questions generally present fewer "traps" and often allow students to directly apply the math skills they know. Consider the problem above.

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  1. Start by Recording What You Know™ and drawing a diagram of our box.
  2. Record any applicable formulas, in this case the formula for the volume of a rectangular solid: l × w × h
  3. Since the walls of the box are all 1 cm thick, to solve for we must subtract 1 cm from each side.
  4. This leaves us with a length of 8 cm, a width of 4 cm, and a height of 6 cm. 
  5. Now we just plug the multiplication into our calculator to get the correct answer, 192 cubic centimeters.

That's it, really!

Know When to Hold 'Em, Know When to Fold 'Em

On GRE Quant, it is essential to employ an effective pacing plan. At PowerScore we recommend students use a Three Pass approach. 

  1. First, do the problems you can solve directly, the problems you can do quickly and without difficulty.
  2. Second, return to the problems that you know you can do but that might require more time or an alternative approach.
  3. Save time to use aggressive problem solving skills on the remaining problems, even if you're just making educated guesses. Remember to leave time to put an answer down for everything at the end.

The problem above is a good example of an opportunity to use your math knowledge to find the answer directly. Of course, you have to have the math knowledge! On our GRE Free Help Area, we have a terrific resource to help you get up to speed with some of these core math skills: GRE Quantitative Reasoning Flash Cards

Download these cards and study them. Mastering GRE Quant is a two step process. First, learn the core math knowledge. Second, learn and practice essential problem-solving and test-taking skills. 

Ask questions about this problem and the other Questions of the Week on our GRE Forums, and don't forget to ask your other GRE questions on the forums. PowerScore instructors monitor the forums and are ready to help. 

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