# GMAT Tip of the Week: The Biggie Smalls Sufficiency Strategy

If it’s March, it must be Hip Hop Month in the Veritas Prep GMAT Tip of the Week space, where this week we’ll tackle the most notorious GMAT question type – Data Sufficiency – with some help from hip hop’s most notorious rapper – Biggie Smalls.

Biggie’s lyrics – and his name itself – provide a terrific template for you to use when picking numbers to test whether a statement is sufficient or not. So let’s begin with a classic lyric from “Big Poppa” – you may think Big is describing how he’s approach a young lady in a nightclub, but if you listen closely he’s actually talking directly to you as you attack Data Sufficiency:

“Ask you what your interests are, who you be with. Things to make you smile; what numbers to dial.”

“What numbers to dial” tends to be one of the biggest challenges that face GMAT examinees, so let’s examine the strategies that can take your score from “it was all a dream” to sipping champagne when you’re thirsty.

Biggie Smalls Strategy #1: Biggie Smalls
Consider this Data Sufficiency problem:

What is the value of integer z?

1) z is the remainder when positive integer y is divided by positive integer (y – 1)

2) y is not a prime number

Statistically, more than 50% of respondents in the Veritas Prep practice tests incorrectly choose answer choice A, that Statement 1 alone is sufficient but Statement 2 alone is not sufficient. Why? Because they’re not quite sure “what numbers to dial.” People know that they need to test numbers – Statement 1 is very abstract and difficult to visualize with variables – so they test a few numbers that come to mind:

If y = 5, y – 1 = 4, and the problem is then 5/4 which leads to 1, remainder 1.

If y = 10, y – 1 = 9, so the problem is then 10/9 which also leads to 1, remainder 1.

If they keep choosing random integers that happen to come to mind, they’ll see that pattern hold – the answer is ALMOST always 1 remainder 1, with exactly one exception. If y = 2, then y – 1 = 1, and 2 divided by 1 is 2 with no remainder. This is the only case where z does not equal 1, but that one exception shows that Statement 1 is not sufficient.

The question then becomes, “If there’s only one exception, how the heck does the GMAT expect me to stumble on that needle in a haystack?” And the answer comes directly from the Notorious BIG himself:

You need to test “Biggie Smalls,” meaning that you need to test the biggest number they’ll let you use (here it can be infinite, so just test a couple of really big numbers like 1,000 and 1,000,000) and you need to test the smallest number they’ll let you use. Here, that’s y = 2 and y – 1 = 1, since y – 1 must be a positive integer, and the smallest of those is 1.

The problem is that people tend to simply test numbers that come to mind (again, over half of all respondents think that Statement 1 is sufficient, which means that they very likely never considered the pairing of 2 and 1) and don’t push the limits. Data Sufficiency tends to play to the edge cases – if you get a statement like 5 < x < 12, you can’t just test 8, 9, and 10 – you’ll want to consider 5.00001 and 11.9999. When the GMAT gives you a range, use the entire range – and a good way to remind yourself of that is to just remember “Biggie Smalls.”

Biggie Smalls Strategy #2:  Juicy
In arguably his most famous song, “Juicy”, Biggie spits the line, “Damn right I like the life I live, because I went from negative to positive and it’s all…it’s all good (and if you don’t know, now you know).”

There, of course, Biggie is reminding you that you have to consider both negative and positive numbers in Data Sufficiency problems. Consider this example:

a, b, c, and d are consecutive integers such that the product abcd = 5,040. What is the value of d?

1) d is prime

2) a>b>c>d

This problem exemplifies why keeping Big’s words top of mind is so crucial – difficult problems will often “satisfy your intellect” with interesting math…and then beat you with negative/positive ideology. Here it takes some time to factor 5040 into the consecutive integers 7 x 8 x 9 x 10, but once you do, you can see that Statement 1 is sufficient: 7 is the only prime number.

But then when you carry that over to Statement 2, it’s very, very easy to see 7, 8, 9, and 10 as the only choices and again see that d = 7. But wait! If d doesn’t have to be prime – primes can only be positive – that allows for a possibility of negative numbers: -10, -9, -8, and -7. In that case, d could be either 7 or -10, so Statement 2 is actually not sufficient.

So heed Biggie’s logic: you’ll like the life you live much better if you go from negative to positive (or in most cases, vice versa since your mind usually thinks positive first), and if you don’t know (is that sufficient?) now, after checking for both positive and negative and for the biggest and smallest numbers they’ll let you pick, now you know.

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By Brian Galvin.

# GMAT Tip of the Week: Cause and Effect

Welcome back to Hip Hop Month in the GMAT Tip of the Week corner. One of the most underrated themes that one can find in 90s rap lyrics is the often-laughable unintentional use of cause-and-effect that rappers draw in their songs, using “(be)cause” as a connector of ideas with hilarious results. Take a line from the refrain of one of Biggie’s biggest hits, Big Poppa:

…You got a gun up in your waist. Please don’t shoot up the place. (Why?) ‘Cause I’ve seen some ladies tonight that should be having my baby…baby…

Really, Big? The primary reason that someone shouldn’t indiscriminately fire a gun around the nightclub is because you have an interest in some of the female patrons? Ethics…legality…these aren’t primary concerns?

Ice Cube has another classic logical misstep in the title single from his cult classic movie Friday, in which he describes some horrific consequences of a disease, followed with the line:

And that ain’t cool, fool, ’cause it’s Friday.

Again, the logic is ridiculous. Any other day of the week would be fine for the kind of (explicitly-described) pain and suffering that he predicts? Just not heading in to the weekend?

As a favor to yourself, listen to your favorite hip hop lyrics from the 90s and seek out the comical cause-and-effect relationships that the rappers draw. It can be incredibly entertaining, and may also help you with your approach to Reading Comprehension questions on the GMAT. How?

When Reading Comprehension questions ask for specific details, they often ask you for either the cause or the effect of a cause/effect relationship. Questions can take the form of:

According to the passage, plants in desert regions can survive for weeks without rainwater because…

or

According to the passage, which of the following results from desert plants’ retention of groundwater?

In either case, you’re likely to return to the passage to analyze the portion that deals with desert plants and how they retain water. However, each question is asking for something completely different. The first asks for the cause of the plants’ survival, while the second asks for the effect of the plants’ water retention. Either question could have the same set of answer choices, and the passage will likely be written in a way that the intended answer to the question – cause or effect – will be a step farther from the key words (maybe “desert plants”) for which you will be looking. The authors of these questions know that, when pressed for time and reading a passage that doesn’t fall within your typical range of expertise, you’re apt to simply find the answer choice that comes closest to the keywords from the passage and feel comfortable selecting that. In many cases, that answer choice will be the trap answer, giving you the cause if they ask for the effect, or vice versa.

To maximize your score on Reading Comprehension questions, look for and internalize the cause-and-effect relationships that are the subjects of the questions, and make sure that you know exactly which end the question seeks. Much like it will enhance your enjoyment of rap lyrics, isolating and focusing on cause-and-effect relationships will improve your score on the GMAT. And that’s cool, you know, because it’s Friday.

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