Two Q's from Set 22

[76mar]

--------------------------------

If x(x - 5)(x + 2) = 0, is x negative?

(1) x2 – 7x ≠ 0

(2) x2 –2x –15 ≠ 0

A. Statement (1) ALONE is sufficient, but statement (2) alone is not22 sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE insufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

 

 

For the above one, I thought answer was B;

 

---------------------------------------------

For a nonnegative integer n, if the remainder is 1 when 2n is divided by 3, then which of

the following must be true?

I. n is greater than zero.

II. 3n = (-3)n

III. √2n is an integer.

A. I only

B. II only

C. I and II

D. I and III

E. II and III

 

I found the answer through substitution; Wanted to know, whether there are any better approaches.

[praneets_1]

Hi 76mar,

1) Ans is C. From the question, we get x=0,5,-2

From statement 1, we know that x not equal to 0and 7 that means x can be 5 or -2

From statement 2, we know that x not equal to 5 or -3 that means x can be 0 or -2.

 

Since 0 is neither a +ve nor a -ve integer, we cannot conclude whether x is negative or not.

But combining both the statements,we can say that x is -2 hence its -ve

 

2) ans is A.

 

Since n is a non negative integer n>=0

 

0 does not satisfy the condition given in the question,therefore n > 0

 

B is false cos the condn 3n =-3n is possible only for n = 0, whcih is ruled out

 

C is false cos for n= 2 sqrt of 2n is an integer while for n = 11 sqrt of 2n is not an integer

 

Do you have any soft copies of gmat material (quant and verbal)?If yes, pls send them across... Thanx in advance. My mail id is praneets1@yahoo.com,praneets_1@yahoo.co.in

 

 

Bye,

Praneet