Problem Solving

Please post only one question per thread. Otherwise things can become pretty complicated when there are discussions on multiple questions.

Cheers,
Brent

In the figure above, points P and Q lie on the circle with center O. What is the value of S?

a) 1/2
b) 1
c) √2
d) √3
e) (√2)/2

Here's one approach:


So, s = 1
Answer: B

Cheers,
Brent

Hi MarceloBR,

Brent's posted a full explanation for this question, so I won't rehash it here. Instead, I want to point out the importance of certain "math" ideas that you'll find useful on the GMAT:

1) Any diagonal line segment on a graph forms the hypotenuse of a right triangle. You can figure out the base and height of this right triangle, so you can figure out the length of the diagonal line.

2) GMAT questions are often based on patterns, so there are rarely any co-incidences in the numbers that appear, the wording of the question or how the answer choices are designed. Here, you should recognize that root3 and 1 are numbers that appear in a very specific type of right triangle. Those numbers are NOT by accident; they're there to test your ability to spot (and take advantage of) a math pattern.

GMAT assassins aren't born, they're made,
Rich

Hi j_shreyans,

The first question can also be solved by TESTing Values:

We're told that the letter I = one's annual income. Since the letter "I" looks like a 1, I'm going to use the letter L to represent the income instead.

L = annual income

Let's TEST...

L = 100

According to the prompt, we have to take 2 percent of L and add it to the average of 100 and 1 percent of L....

.2(100) + [100 + .01(100)]/2

2 + 101/2

2 + 50.5

52.5

This is the number we're looking for in the answer choices when we plug in 100.

Only answer C matches.

GMAT assassins aren't born, they're made,
Rich