How to Solve a Mathematics Word Problem on the GRE
When you have to translate a word problem into math on the GRE, knowing where to start is often the most daunting challenge. The key is to begin with what you know and work toward what you don’t know. You can solve almost all word problems by taking the following step-by-step approach:
Read the entire problem carefully.
A question may provide three values and then ask for the total or the average. You may not know until the very end of the question what it’s asking you to determine, so read the entire question.
Write down all the values and units that you know.
When you see all the pieces, the solution to the problem often reveals itself. Values are the clues you need to solve the mystery.
Identify what the question is asking you to find.
Look for words such as what is, how much, how many, how fast, at what price, and so on. Whatever the question asks you to find is the unknown; you can call it x.
Construct the mathematical equation, plugging in all known values and the x.
In most cases, the word problem is a specific type requiring a special equation. With this equation, known values, and x in hand, you have what you need to solve the problem.
Solve the equation.
When you have everything in place, do the math.
Make sure your answer fits with common sense.
The advantage of most word problems is that they’re set in the context of a story, so you can use your common sense to gauge whether the answer is reasonable. Suppose you solve a distance-rate-time problem and find that Grandma was driving 600 miles per hour. Your common sense tells you that this isn’t right, so you can check your work instead of moving on. This strategy is especially useful when you’re asked to type the answer rather than select it from a list.