alimad wrote:

Another few questions that needs some answer. By the way thanks for you help in answering my first query .

1. If 3 and 8 are the lengths of two sides of a triangular region, which of the following can be the length of the third side?

I. 5

II. 8

III. 11

(A) II only

(B) III only

(C) I and II only

(D) II and III only

(E) I, II and III

This is simply a question about the Triangle Inequality. Here's a GMAT blog that discusses these:

http://magoosh.com/gmat/2012/facts-abou ... -the-gmat/All the possible lengths must be greater than 8-3 = 5 and less than 8 + 3 = 11, so

(A) is the answer.

alimad wrote:

2. The size of a television screen is given as the length of the screen's diagonal. If the screen were flat, then the area of a square 21 - inch screen would be how many square inches greater than the area of a square 19- inch screen?

(A). 2

(B). 4

(C). 16

(D). 28

(E). 40

I don't like this question, only because real television screens are not square! Good GMAT questions are totally realistic in the data they cite in word problems.

Having said that, I'll solve this. This link discusses the 45-45-90 triangle (a.k.a. the Isosceles Right Triangle), which plays into this calculations.

http://magoosh.com/gmat/2012/the-gmats- ... triangles/If 19 is the diagonal, then \(\frac{19}{sqrt(2)}\) is the length of the side, and the area is \(\frac{19^2}{2}\). Without a calculator, I don't want to calculate that if I don't have to.

If 21 is the diagonal, then \(\frac{21}{sqrt(2)}\) is the length of the side, and I am going to write that as \(\frac{19+2}{sqrt(2)}\), and when we square that we get

\(\frac{(19+2)^2}{2}=\frac{19^2 + 2*2*19 + 2^2}{2}\)

Subtract the first area, and we are left with

difference in area = \(\frac{2*2*19 + 4}{2}\) = 2*19 + 2 = 38 + 2 = 40

Answer =

(E)alimad wrote:

3. If x is an integer and Y = 3x + 2, which of the following CANNOT BE A DIVISOR of Y?

(A). 4

(B). 5

(C). 6

(D). 7

(E). 8

Here's a blog on factors that might be germane.

http://magoosh.com/gmat/2012/gmat-math-factors/Well, we know 3x will be divisible by 3, and if we add 2, we know we create a number that

never will be divisible by 3. If Y is not divisible by 3, then it's not divisible by 6.

Answer =

CLet me know if anyone reading this has any questions.

Mike

_________________

Mike McGarry

Magoosh Test Prep

Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)