### How to Tackle Every Single GMAT Problem (Seriously!) – Part 4

Welcome to the fourth installment of our series: how to tackle every problem on the GMAT. If you’re joining in the middle, go back and learn about the set of principles that tie together everything we need to do on the GMAT. Then work your way back to this installment.

Here’s our framework again:

I finished off part 3 with the following GMATPrep® problem from the free exams. Let’s use the SC process to answer it now. Read more

### The Importance of Getting to No on the GMAT — Part 2

Last time, we talked about how crucial it is to develop the instinct to go for the “No” when taking the GMAT. If you haven’t read the first installment, do so right now, then come back here to learn more.

I left you with this GMATPrep® problem from the free exams.

“*If 0 <

r< 1 <s< 2, which of the following must be less than 1?“I.

“II.

rs“III.

s–r“(A) I only

“(B) II only

“(C) III only

“(D) I and II

“(E) I and III”

Let’s talk about it now!

### GMAT Challenge Problem Showdown: December 16, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

A set of

nidentical triangles with anglex° and two sides of length 1 is assembled to make a parallelogram (ifnis even) or a trapezoid (ifnis odd), as shown. Is the perimeter of the parallelogram or trapezoid less than 10?

### GMAT Challenge Problem Showdown: December 2, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

An isosceles triangle with one angle of 120° is inscribed in a circle of radius 2. This triangle is rotated 90° about the center of the circle. What is the total area covered by the triangle throughout this movement, from starting point to final resting point?

(A)

(B)

(C)

(D)

(E)

### GMAT Challenge Problem Showdown: October 21, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

A sheet of paper

ABDEis a 12-by-18-inch rectangle, as shown in Figure 1. The sheet is then folded along the segmentCFso that pointsAandDcoincide after the paper is folded, as shown in Figure 2 (The shaded area represents a portion of the back side of the paper, not visible in Figure 1). What is the area, in square inches, of the shaded triangle shown?

### GMAT Challenge Problem Showdown: October 14, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

If

a,c,d,x, andyare positive integers such thatay<xand is the lowest-terms representation of the fraction , thencis how much greater thand? (If is an integer, letd= 1.)(1) is an odd integer.

(2)

a= 4

### GMAT Challenge Problem Showdown: October 7, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

The positive number

aisqpercent greater than the positive numberb, which isppercent less thanaitself. Ifais increased byppercent, and the result is then decreased byqpercent to produce a positive numberc, which of the following could be true?I.

c>a

II.c=a

III.c<a

### GMAT Challenge Problem Showdown: September 30, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

For how many different pairs of positive integers (

a,b) can the fraction be written as the sum ?

### GMAT Challenge Problem Showdown: September 16, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

If

aandbare different nonzero integers, what is the value ofb?(1)

a=^{b}ab(2)

a–^{b}a^{b}^{ – 1}= 2

### GMAT Challenge Problem Showdown: September 9, 2013

We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

A semicircular piece of paper has center

O, as shown above. Its diameterA’Ais coated with adhesive. If the adhesive is used to fuse radiiOA’andOAalong their entire lengths (so that pointsAandA’ coincide, pointsPandP’ coincide, and so on), a cone is formed as shown above. If pointBdivides the original semicircle into two identical arcs, what is the measure of angleAOBin the folded cone?