5Tips for Tackling Problem Solving Questions1. Always plugin values into equations whereever you can.You don't always need to solve questions. This is the GMAT, you get rewarded for being smart. The test makers have given you 5 choices, so you know that the answer is already in front of you. So why not just try a few answer choices to see if something clicks?For example, if the questions contains a couple of equations (x+3y=2 and x-y=-1) and the answer choices have been given as x,y value pairs x=0, y=2 etc. You don't really need to solve the equations do you? You can simply plugin the values of x and y into the equations and see which one fits both the equations.
2. Always plug in values starting from choice (E). The test makers aren't that easy to fool though. You know that they know that you can plugin values. So, they always provide answer choices such that if you plugged that value into one of the equations (continuing the previous example), the answer choice would seem to be a fit! That's how they trick you. Usually, choice (B) or (C) would be such that when you plug values from that into the equation, it will apparently provide the solution. So, we go even one step further and bypass the test maker's trap. We start from choice (E). That way, instead of falling for the trap, we just get to the answer faster.
3. Know what you don't know.One of the hardest concepts in life and indeed on the GMAT is that of quitting. We're taught as a child to "never give up". Society,family, movies, our beloved simpsons character, all try to teach us to "never give up".But, as the old saying goes,"If you don't quit while you have the choice, life may not give you the choice to quit later". And for those who have that ego that doesn't let them quit, remember this saying, "Trees that do not learn to bend to the wind, are taught how to when the wind breaks off their branches".Now, that I've given you the positive philosophical pep talk, let us come back to the GMAT. On the GMAT you have to give up. You need a quitting strategy. Quit early and quit often is the real mantra. Of course, that does not mean you need to quit as soon as you see a question. You should try to solve the question.But, there is an exception to that rule.IF you know that you don't understand the concept or are usually wrong at a particular kind of question, what sense does it make to spend time on that question? The GMAT is a timed test, and you probably won't get another similar question during the test, so why not let that question go. Guess and move on!For example, say Joe Shmoe did not know probability. And on the GMAT he runs into a probabilty question. Now, he THINKS he knows a formula, and so he tries that formula, and seems to get an answer that matches one of the choices. He spent 3 minutes on this question. He later realizes that he applied the wrong formula and wasted 3 minutes. 3 minutes on quant mean 3 solved questions, so imagine his plight when he has to leave 3 questions at the end of the quant section because of timing issues. I hope the example clarifies the point I'm trying to make. You need to know what you don't know. So that you can let certain questions go on the real test.
4. Always draw a number line wherever applicable.A number line is a great thing. On the GMAT, you may get a question related to fractions, or ranges, or integers, or a number theory related question. There is a very efficient way of solving these questions, and that is by using a number line.For example, let us say you are asked to find out which one of 5 fractions (signed) is the smallest, chances are you could be confused. With the long history of GMAT test takers, you probably will be.That is why, representing values on the number line is an effective strategy. Avoid the confusion and get to the answer faster.
5. Always check for unitsThis is so basic, and yet, we all have made this mistake at one time or another. You solve a problem solving question and you're really excited to click on the answer choices. You click on the answer choice and then just as you click next, you realize that the question demanded an answer in inches and you gave an answer in centimeters. Sadly, you can't go back on the GMAT.Avoid that experience. Always check for units and measurements. Are they asking for an answer in pounds or kilograms, inches or centimeters, etc. The test makers also provide conversion ratios wherever needed, so you can use them to answer the question correctly. That's the max anybody can do for you. So, always check the units, convert to the right units and score well on the PS.