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Solving GMAT Quant questions involving pyramids by Economist GMAT

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Solving GMAT questions with pyramids Geometry is the area of GMAT math that requires you to memorize the greatest number of formulas. The good news is that once you have done this, you have gone a long way towards solving most geometry questions. Consider the following Data Sufficiency problem from Economist GMAT Tutor 's bank of 5000+ practice questions: What is the volume of pyramid P? (1) The height of pyramid P is 7.
(2) The base of pyramid P is of area 5.
When answering Data Sufficiency questions, it is a good idea to ask yourself: “What do I need to know to answer the question?”
In this case, you will need to recall that the volume of a pyramid = 1/3 × area of the base × height.
Now look at both statements together. They give you both pieces of information you need to solve the question. Stat.(1)+(2)->S->C. It’s important to know that since you have the pieces of relevant information, you do not actually have to compute the volume -- that would take too much time! To consolidate your knowledge of pyramids, consider another practice question from our bank of practice questions: If pyramid P and rectangular box B are of equal height, what is the ratio, by volume, of P to B? (1) Pyramid P and rectangular box B have square bases.
(2) Pyramid P and rectangular box B have bases of equal area.
Again, ask yourself what you need to answer the question. Start by thinking about the volume formulas for each: To determine the ratio, by volume, of a pyramid and a rectangular box that are of equal height, you need to know the ratio of the area of the base of the pyramid to the area of the base of the box, since the base would be length × width. The main takeaway from both of these questions is the formula for calculating the volume of a pyramid. During your preparation you will come across many formulas that you will need to commit to memory for test day, and this is one of them. As you continue to learn (or re-learn) the formulas necessary for GMAT Quant success, be sure that you maximize efficiency by organizing the formulas into an accessible list for review.
This article first appeared here Solving GMAT Quant questions involving pyramids by Economist GMAT

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