Browsing articles tagged with ""
Apr
3
2013

# A Timing Trick for GRE Quantitative Comparisons

“I’m fine with the problems. It’s the timing that kills me.”

I hear this from a lot of you. Unfortunately, as I explained recently, having more time on the GRE wouldn’t actually help you get a higher score, since the GRE is a scaled test. So let’s leave the complaining to our competition, shall we? Instead of moaning about the clock, strive be as awesome as you can at solving problems. If you’re great, you’ll also be fast. Here’s a quantitative comparison that’s pretty simple, but also a nice illustratration of the fact that speed isn’t something that comes independently of problem solving skill.

This problem, like several I’ve been looking at recently, comes from our GRE Bootcamp event:

Quantity A: The sum of all integers from 9 to 29, inclusive

Quantity B: The sum of all integers from 12 to 30, inclusive

At a glance, the “math” way to solve this problem is time-consuming but direct: add up the sums in both columns, then compare. Since there’s an on-screen calculator on the GRE, some of your competition will solve the problem this way. And boy does it take a long time.

Let me be very clear: directly totaling both columns isn’t just a slow way to solve the problem. It’s a BAD way. Someone who solves the problem in this head-on, brute force fashion, then says to themselves, “I’m fine with the problems, it’s the timing that kills me,” is being dishonest with themselves. They are not ”fine with the problems.” They are very much unfine!

Instead, when you have to compare two quantities, start by eliminating what they have in common. If a quantity appears in both columns, then it isn’t helping either one to be bigger than the other.

Here, both columns include the range of numbers 12-29. Thus, totaling that range would be a waste of time. Ignore it and look instead at what’s different:

Quantity A: The sum of all integers from 9 to 11, inclusive

Quantity B: The of all integers from … never mind, it’s just 30!

And since 9 + 10 + 11 clearly equals 30, you can click choice (C) — “The two quantities are equal” — in under 10 seconds and score the point. That’s the beauty of the GRE: if you’re awesome, speed comes for free. Practice will get you there!

Mar
27
2013

# GRE Reading Comp Logic: the Wrong Rabbit Hole

Last year, I wrote a series of entries about the critical reasoning problems that were recently added to the GRE. Since it’s been a while, let’s revisit that question type — and check out another aspect of critical thinking that confounds many of you.

Here’s a type of problem that’s caused no end of consternation to a lot of my students:

Residents of this state are obligated to renew their driver’s license in two circumstances only: if they accumulate six or more points in moving violations, or if they obtain citizenship in another country. Clarice, who is a citizen of only this country, has been involved in only one accident, which added three points to her license. Therefore, Clarice has no reason to renew her driver’s license at this time.

The argument above depends on which of the following assumptions?

I’m not going to show you the answer choices because the essence of this problem needs to be taken care of long before you ever look at a single choice. When I ask my students for the assumption, I invariably hear answers such as the following:

- “The author assumes that Clarice didn’t receive points from sources other than accidents.”

- “The author assumes that Clarice wasn’t already a citizen of some other place.”

- “The author assumes that Clarice didn’t do something else that would make her have to renew her license.”

All of these wrong answers fall for the same trap: thinking in the way that the test makers want you to think. The test makers say, “Hey! Look at these conditions. Clarice didn’t meet any of them. So, there’s no reason for her to renew her license.” And a lot people look at that line of reasoning and say, “Aha! I bet Clarice DID meet one of those conditions, in some sneaky way.” Then they start drumming up clever ways to force poor Clarice to retake her driver’s exam.

This is what I like to call going down the wrong rabbit hole. The test makers show you a rabbit hole, saying basically, “Hey, you! Think about THIS.” And so you think about whatever “this” is, and you think about it really hard, and the problem is that you shouldn’t have even started thinking along those lines in the first place.

Let’s back up a bit.

Consider this argument:

Boris isn’t obligated to exercise. Therefore, there is no reason for Boris to exercise.

There is no law mandating that Boris be kind to his mother. Therefore, he should be a jerk to her.

How do those arguments sound? Terrible, you say?! But why? If I’m not required to do something, doesn’t that mean I have no reason to do it?

Here, again, is the argument about Clarice, but condensed to the essentials:

Clarice isn’t required to renew her driver’s license. Therefore, she has no reason to renew her driver’s license.

It’s tricky to spot the error the first time someone throws you an argument like this, because renewing a driver’s license is boring and lame, so your brain fills in the gap in the argument: “The only reason anyone would ever renew their license was if they had to.” But that’s not necessarily true: that’s an assumption. Maybe Clarice gets a tax credit for renewing her license, or renewing the license will get some of her points taken away, or renewing the license provides some other benefit to something completely unrelated. We don’t know.

Remember this nugget of logical wisdom when you take the GRE: just because a person isn’t required to do something, doesn’t mean that they shouldn’t or they won’t!

Mar
25
2013

I love the month of March for a lot of reasons – not only is the weather finally becoming warmer as winter thaws away, but I also get to remind you all of Kaplan’s spring “Try Us For Free” event series! If you’ve ever wondered what a Kaplan class is like, now is your chance to see one of our fabulous Anywhere teachers in action in a virtual classroom, breaking down the GRE and introducing you to proven methods and strategies that will allow you to dominate the competition on Test Day.

If you attended any of the free practice tests that we held recently, then you’ve already gotten to meet some of our great GRE instructors and teaching associates. What better way to continue your GRE prep than to attend a full 90-minute session that’s specifically focused on introducing you to the most efficient approach to every question-type that you’ll see on the GRE?

We have two preview classes coming up, at the following dates and times:

Wednesday, March 27th, 9:30 – 11:00 pm ET

Sunday, April 7th, 5:30 – 7 pm ET

In addition to practice tests and preview classes, we regularly run other seminars – for example, later in April (the 17th, to be exact), we’re hosting a “GRE Challenge” event. To register for any of our events, go to kaptest.com/GRE and type your zip code into the “Free Events” search box, and scroll to the list of “Anywhere” results. We look forward to seeing you at an event soon!

Mar
15
2013

Who else is waiting impatiently for Season 3 of the BBC’s Sherlock? Rumor has it that filming of the new season will begin on March 18. If you are Sherlocked like me and pacing the floors, desperate to find out how he survived, here’s something that can keep you occupied until our beloved Holmes and Watson return to us.

Find solace in what Sherlockians refer to as The Canon – the original works and writings by Arthur Conan Doyle. I recently read A Study in Scarlet (you can read it for free here) and not only was my Sherlockian soul sated, but I also discovered many gems of GRE vocabulary tucked into the text. Give it a read, and keep your vocabulary notebook nearby, as you’re sure to find plenty of words to add to your “To Be Looked Up” list.

Cases of mysterious vocab you will find within A Study in Scarlet include:

desultory

formidable

torpor

genial

zeal

puerile

ineffable

remonstrated

stoicism

jocosely

…among others.

Next up: The Sign of Four. I’m eager to discover the lexicographic lovelies that await me there.

In closing, some words of wisdom for your prep:

Study for the GRE if convenient. If inconvenient, study all the same.

If you’re reading anything that has good GRE vocab in it, we’d love to hear about it! Please share in the comments below.

Mar
6
2013

# GRE Math Trick: Ratio Tables

When a GRE quantitative problem features multiple ratios, many of you suffer headaches. This is because the “math” way of solving the problem is brutal, and students who don’t use logic will dive head-first into a morass of ugly substitutions, mistakenly assuming that the GRE is a math test. Here’s the kind of problem I’m talking about:

In a particular mixed candy bag, the ratio of Skittles to M&M’s is 4 to 5, while the ratio of Reese’s Pieces to M&M’s is 9 to 7. What is the ratio of Skittles to Reese’s Pieces?

The “math” way to do this problem is to set up two equations, solve one for M&M’s, and plug that value into the other one. If that sounds painful, that’s because it is. Don’t do this. Make a simple table instead:

```S | M | R 4 : 5     7 : 9```

Take a moment to confirm that you understand where the numbers above are coming from. They’re just a translation of the information in the word problem.

The question asks for the ratio of S to R. Can you just say it’s 4 to 9? No way. The value connecting them — the M — is different. It’s 5 in one ratio and 7 in the other. So, rewrite the ratios to make the M term the same in both, creating a kind of “bridge.”

```Multiply the first ratio by 7:  7×(4:5) = 28:35 Multiply the second ratio by 5: 5×(7:9) = 35:45```

Next, check out your new table:

```S  |  M |  R 28 : 35      35 : 45```

Now you can just “walk across the bridge,” as it were — the ratio of S to R is simply 28:45. Try this technique on your next multiple-ratios problem and let us know how it goes!

Pages:1234567...13»