GMAT Tip of the Week The Least Helpful Waze To Study

If you drive in a large city, chances are youre at least familiar with Waze, a navigation app that leverages user data to suggest time-saving routes that avoid traffic and construction and that shave off seconds and minutes with shortcuts on lesser-used streets. And chances are that youve also, at some point or another, been inconvenienced by Waze, whether by a devout user cutting blindly across several lanes to make a suggested turn, by the app requiring you to cut through smaller streets and alleys to save a minute, or by Waze users turning your once-quiet side street into the Talladega Superspeedway. To its credit, Waze is correcting one of its most common user complaints  Ã‚  that it often leads users into harrowing and time-consuming left turns. But another major concern still looms, and its one that could damage both your fender and your chances on the GMAT: Beware the shortcuts and crutches that save you a few seconds, but in doing so completely remove all reasoning and awareness. With Waze, weve all seen it happen: someone so beholden to, I must turn left on 9th Street because the app told me to! will often barrel through two lanes of traffic with no turn signal to make that turnnot realizing that the trip would have taken the exact same amount of time, with much less risk to the driver and everyone else on the road, had he waited a block or two to safely merge left and turn on 10th or 11th. By focusing so intently on the apps dont worry about paying attentionwell tell you when to turn features, the driver was unaware of other cars and of earlier opportunities to safely make the merge in the desired direction. The GMAT offers similar pitfalls when examinees rely too heavily on turn your brain off tricks and techniques. As you learn and practice them, strategies like the plumber butt for rates and averages may seem quick, easy, and turn your brain off painless. But the last thing you want to do on a higher-order thinking test like the GMAT is completely turn your brain off. For example, a turn your brain off rate problem might say: John drives at an average rate of 45 miles per hour. How many miles will he drive in 2.5 hours? And using a Waze-style crutch, you could remember that to get distance you multiply time by rate  so  youd get 112.5 miles. That may be a few seconds faster than performing the algebra by thinking Rate = Distance over Time; 45 = D/2.5; 45(2.5) = D;  D = 112.5. But where a shortcut crutch saves you time on easier problems, it can leave you helpless on longer problems that are designed to make you think. Consider this Data Sufficiency example: A factory has three types of machines A, B, and C each of which works at its own constant rate. How many widgets could one machine A, one Machine B, and one Machine C produce in one 8-hour day? (1) 7 Machine As and 11 Machine Bs can produce 250 widgets per hour (2) 8 Machine As and 22 Machine Cs can produce 600 widgets per hour Here, simply trying to plug the information into a simple diagram will lead you directly to choice E. You simply cannot separate the rate of A from the rate of B, or the rate of B from the rate of C. It will not fit into the classic rate pie / plumbers butt diagram that many test-takers use as their I hate rates so Ill just do this trick instead crutch. However, those who have their critical thinking mind turned on will notice two things: that choice E is kind of obvious (the algebra doesnt get you very close to solving for any one machines rate) so its worth pressing the issue for the reward answer of C, and that if you simply arrange the algebra there are similarities between the number of B and of C: 7(Rate A) + 11(Rate B) = 250 8(Rate A) + 22(Rate C) = 600 Since 11 is half of 22, one way to play with this is to double the first equation so that you at least have the same number of Bs as Cs (and rememberthose are the only two machines that you dont have together in either statement, so relating one to the other  may help). If you do, then you have: 14(A) + 22(B) = 500 8(A) + 22(C) = 600 Then if you sum the questions (Where does the third 22 come from? Oh, 14 + 8, the coefficients for A.), you have: 22A + 22B + 22C = 1100 So,  A + B + C = 50, and now you know the rate for one of each machine. The two statements together are sufficient, but the road to get there comes from awareness and algebra, not from reliance on a trick designed to make easy problems even easier. The lesson? Much like Waze, which can lead to lack-of-awareness accidents and to shortcuts that dramatically up the degree of difficulty for a minimal time savings, you should take caution when deciding to memorize and rely upon a knee-jerk trick in your GMAT preparation. Many are willing (or just unaware that this is the decision) to sacrifice mindfulness and awareness to save 10 seconds here or there, but then fall for trap answers because they werent paying attention or become lost when problems are more involved because they werent prepared. So,  be choosy in the tricks and shortcuts you decide to adopt! If a shortcut saves you a minute or two of calculations, its worth the time it takes to learn and master it (but probably never worth completely avoiding the long way or knowing the general concept). But if its time savings are minimal and its grand reward is that, Hey, you dont have to understand math to do this! you should be wary of how well it will serve your aspirations of scores above around 600. Dont let these slick shortcut waze of avoiding math drive you straight into an accident. Unless the time savings are game-changing, you shouldnt make a trade that gains you a few seconds of efficiency on select, easier problems in exchange for your awareness and understanding. Getting ready to take the GMAT? We have free online GMAT seminars running all the time. And as always, be sure to follow us on  Facebook, YouTube,  Google+  and Twitter! By Brian Galvin.