If n is odd, is x+1 odd? 1. x=n+1 2. n=13

Question

If n is odd, is x+1 odd?

1. x=n+1
2. n=13

Folaa3 · Answer

Answer is C. 

Be mindful that n though odd, could be positive or negative so looking at 
Statement 1, x = n + 1
X= -9 + 1 = -8 (even)
-8 + 1 = -7

X = 9 + 1= 10
10 + 1 = 11

So statement 1 is insufficient. 

Statement says n = 13, but we donâ€™t know what x is so insuff

Combining both statements, if n = 13 and x = n + 1, then 13 + 1 = 14 and 14 + 1 = 15 thus x + 1 is odd.

Dilshod · Answer

Folaa3
Indeed, the OA is (A).
But suppose that n=-1, then x would be (0). Is 1 considered odd?

mandy · Answer

another A st2 INSUFFICIENT ST 1 x=n+1 n odd n+1 =ODD +1 = even so x is even so x+1 IS ODD SO A :wink:

Dilshod · Answer

I repeat again, is (-1) considered odd?

july05 · Answer

i think -1 is considered odd just like 1

Dilshod · Answer

What about (0)?
In some theoretical books I have read, (0) was considered both even and odd.

qpoo · Answer

A

2)alone is insufficient but 1) is

ssap · Answer

Odd numbers can be positive or negative integers -3, -1, 1, 3 etc
Ditto for even number : -4, -2, 2 etc
Zero is an EVEN integer.
This is a very important piece of trivia which seems to be a favorite of ETS test makers.

If n is odd, is x+1 odd? 1. x=n+1 2. n=13

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