Cambridge tests - good one

[arora007]

IF N>0, is N a whole number?
1) 3*N is an odd number
2) 2*N is an even number

[spoiler]
I chose D, but the answer is correctly B.[/spoiler]

[advita]

B.
1.n=1, or 1/3
2.n is integer...whole number so B.

[Night reader]

Every whole number can be expressed as fraction --> 2 and 4/2 5 and 15/3; we just need to observe (+-) ve sign which is given here N>0. Still given N>0 as odd and even can be extended to negatives as well and whole numbers are only +ve (we know that N>0, so it's clean assumption here that N could be a whole number)

The point is N as 2 can be also 4/2 and 4/2 is not a whole number but 2 is the whole number.

IF N>0, is N a whole number?
1) 3*N is an odd number
2) 2*N is an even number

[spoiler]
I chose D, but the answer is correctly B.[/spoiler]

[arora007]

I believe that whole numbers are positive intergers and zero .

i.e. Whole numbers are natural nos Union Zero.

https://www.mathsisfun.com/whole-numbers.html

[Night reader]

yes certainly and every whole number can also be a fraction 4/2 is the fraction, nominally, but 2 is a whole number. It's like various quadrilaterals in Geo can be this and that at the same time.

I believe that whole numbers are positive intergers and zero .

i.e. Whole numbers are natural nos Union Zero.

https://www.mathsisfun.com/whole-numbers.html

[mk101]

IF N>0, is N a whole number?
1) 3*N is an odd number
2) 2*N is an even number

[spoiler]
I chose D, but the answer is correctly B.[/spoiler]

shouldnt the answer here be E.

Statement 2 : for N = 1 OR 0 OR -1 THE value of 2 *n = even

[mk101]

@nightreader, thanx... guess I missed n>0

[ankurmit]

@Night reader ..I could not understand your explanation.

Can you please elaborate

[Ashish8]

Night Reader, then what would your answer be?

To my knowledge 4/2 is a whole number on the GMAT.

I also agree that B is the correct answer.

[Night reader]

it's B never mind

Night Reader, then what would your answer be?

To my knowledge 4/2 is a whole number on the GMAT.

I also agree that B is the correct answer.

[[email protected]]

IF N>0, is N a whole number?
1) 3*N is an odd number
2) 2*N is an even number


Stimulus: If N>0 and when N is a whole number, it is implied that basically you are looking only for the positive integers. So the basic question is that IS N A POSITIVE INTEGER.


STATEMENT 1: If 3N is an odd number, then there are two cases here.

Case(i): If N is a positive fraction i.e if N is 1/3, then 3N would be 1 and so N is not a positive fraction.

Case(ii): If N is any positive integer i.e if N is 1,2,3...., then 3N would be an odd number and so N is a positive integer.

Because there are 2 answers, i.e N can be a positive integer or might not be a positive integer.
Hence statement 1 is insufficient.


STATEMENT 2:
2*N is an even number

Even when you take N as 1/2, 2N will be 1 which is not even. So you need an even number and for that N has to be a positive integer. Because if you try some other fraction, then 2N shall no longer be an even number. By the way remember that an even number is by defination a positive integer as it is also mentioned that N>0 so 2N cannot be a negative even integer.

Because there is only 1 possibility remaining, then statement 2 is sufficient.

Hence the correct answer is B.

Hope this clear and concise post helps you guyzzzz...