If m and n are integers, are they consecutive numbers?

Question

(1) mn + 1 is even.
(2) mn < m^2 + m

rohit8865 · Answer

(1) since mn+1=even
then mn must be odd no. 
so m & n are odd nos.
thus are not consecutive....suff

(2)m(n-1)<m^2

if m=1 & n=0 then Yes 
if m=5 , n=0 then No
insuff

Ans A

vitaliyGMAT · Answer

I have another thoughts. Please correct me if i'm wrong. (1) mn + 1 is even. mn = odd m-odd, n - odd sufficient. (2) mn < m^2 + m n < m + 1 ----> n - m < 1 and m - n > -1 Because n and m are integers we have only one possible soluion n - m = 0 or n = m Sufficient. Answer D

rohit8865 · Answer

vitaliyGMAT

highligted part is incorrect ...
u cannot cancel m from both side until it is given m>0

Hope it helps

If m and n are integers, are they consecutive numbers?

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