Welcome back to Hip Hop Month in the GMAT Tip of the Week space, where 3-13 isn’t just a day to honor Eminem’s group “Three and a Third” from 8 Mile (we’ll save that for 10/3). It’s also Common’s birthday, so what better day to let one of the most intellectual rappers in the game help you take your game toward his South Side neighborhood (Chicago-Booth isn’t all that far away) or, we suppose, to the North Side and Kellogg?
Now, while you’re in the thick of the quant section looking for an un-Common-ly high score, the only Common lyric in your head is probably “Go!”. But particularly when you get to dense word problems, you’ll likely have more success if you heed his advice from the beginning and the refrain from “The Food“:
Slow motion better than no motion.
What’s Common trying to tell you about how to approach the quant section? Essentially this: most examinees hurry through their initial read of a problem, taking ~20 seconds to read the entire paragraph prompt, only to get to the question mark, sigh, and go back to the top to get started. That’s “no motion” on your first 20 seconds – which, if you’re holding to an average of 2 minutes per problem, is almost 17% of the time you have to get it done.
What should you do? Slow motion, which is better than no motion. What does that mean? Start writing and thinking while you read. For example, consider this problem:
Working in a South Side studio at a constant rate, Kanye can drop a full-length platinum LP in 5 weeks. Working at his own constant rate, Common can drop a full-length platinum LP in x weeks. If the two emcees work together at their independent rates, they can drop a full-length platinum compilation LP in 2 weeks. Assuming no efficiency is lost or gained from working together, how many weeks would it take Common, working alone, to drop a full-length platinum LP?
(A) 3 and 1/3 weeks
(B) 3 weeks
(C) 2 and 1/2 weeks
(D) 2 and 1/3 weeks
(E) 2 weeks
Now, while your instinct may be to Go! and speed through your initial read of this rate problem, remember: slow motion (is) better than no motion. As you read each sentence, you should start jotting down variables and relationships so that by the time you get to the question mark you have actionable math on your noteboard and you don’t have to read the question all over again to get started. You should be thinking:
Working in a South Side studio at a constant rate, Kanye can drop a full-length platinum LP in 5 weeks.
Rate (K) = 1 album / 5 weeks
Working at his own constant rate, Common can drop a full-length platinum LP in x weeks.
Rate (C) = 1 album / x weeks
If the two emcees work together…
I’m adding these rates, so their combined rate is 1/5 + 1/x
…they can drop a full-length platinum compilation LP in 2 weeks.
And they’re giving me the combined rate of 1 album / 2 weeks, so 1/5 + 1/x = 1/2
Assuming no efficiency is lost or gained from working together, how many weeks would it take Common, working alone, to drop a full-length platinum LP?
I’m using that equation to solve for Common’s time, so I’m solving for x.
Now by this point, that slow motion has paid off – your equation is set, your variable is assigned, and you know what you’ve solving for. Your job is to solve for x, so:
1/5 + 1/x = 1/2, so let’s get the x term on its own:
1/x = 1/2 – 1/5. and we can combine the two numeric terms by finding a common denominator of 10:
1/x = 5/10 – 2/10
1/x = 3/10, and from here you have options but let’s cross multiply:
10 = 3x, so divide both sides by 3 to get x alone:
10/3 = x, and that doesn’t look like the answer choices so let’s convert to a mixed number: 3 and 1/3 (there’s that number again), for answer choice A.
What’s the real lesson? It’s like Common says: slow motion (is) better than no motion, so you should read just a little slower but have some scratchwork to show for your initial read of the prompt. If you can:
-jot down relationships or equations
-write down which variable the answer wants
You’ll have a lot more to show for your initial 30 seconds with each problem, and you’ll find that you solve problems much more quickly this way because you have less wasted time. So heed Common’s uncommon wisdom (which is really just common sense): the best way to Go is to remember that slow motion > no motion.
By Brian Galvin