if m is an odd integer and n an even integer, which of the following is definitely odd?
a)(2m+n)(m-n)
b)(m+n^2)(m-n^2)
c)m2+mn+n2
d)m+n

• m+n will be always odd,if one number is odd,and other is even ,then it always odd,
  so d)m+n is right answer(ans)
• 11 years agoHelpfull: Yes(60) No(7)
• You just remember the following odd ± odd = even; even ± even = even; even ± odd = odd
  Also odd x odd = odd; even x even = even; even x odd = even.
  
  
• 10 years agoHelpfull: Yes(7) No(4)
• D is the right answer
  odd+ even= odd
• 10 years agoHelpfull: Yes(3) No(3)
• D) m+n will be the definite answer
  
• 9 years agoHelpfull: Yes(3) No(2)
• both c and d will be correct for this question
• 8 years agoHelpfull: Yes(3) No(2)
• Both C and D are correct....but since its a dummy question...thus selecting a particular answer may cause u negative marking..thus advised not to attend this type of questions with multiple answers....
• 8 years agoHelpfull: Yes(3) No(2)
• This is a very tricky question. If we put any value at option (c) and (d) both will give us odd result.
  But option C is not a correct one. Because the actual expression is m^2+m*n+n^2. Now this can be written as (m^2+m)*(n+n^2) which gives us even result.... u can check this out.... So option (d) is "definitely odd".
• 8 years agoHelpfull: Yes(3) No(0)
• m+n suppose m=1 & n=0
• 9 years agoHelpfull: Yes(2) No(0)
• m+n is definitely odd
• 8 years agoHelpfull: Yes(2) No(1)
• m+n is definitely odd.
  sum of even and odd is always odd.
• 9 years agoHelpfull: Yes(1) No(0)
• The odd number is (m+n ) because sum of an even number and an odd number is always an odd number.
• 8 years agoHelpfull: Yes(1) No(0)
• y not option b is correct can some oone explain?
• 8 years agoHelpfull: Yes(0) No(0)
• Ans is option d (m+n) always odd
• 8 years agoHelpfull: Yes(0) No(1)
• the_answer_is_(d).
• 8 years agoHelpfull: Yes(0) No(0)
• very easy questiion
• 8 years agoHelpfull: Yes(0) No(0)
• sum of even and odd no is always odd
  so, m+n is definitely odd
• 8 years agoHelpfull: Yes(0) No(0)
• both c & d
• 8 years agoHelpfull: Yes(0) No(4)
• C is incorrect.... you can try it with any odd and even number pair. For example (i) (7,4) 7x2+7x4+4x2 => 14+28+8 = 50. (ii) (1,2) 1x2+1x2+2x2 = 2+2+4 = 8.
  D is the correct ans only.
• 8 years agoHelpfull: Yes(0) No(2)
• How C & D both are correct? Can anyone please quote some example in favor of option C !!!!
• 8 years agoHelpfull: Yes(0) No(0)
• is it a dummy ques or the ans is d...but it seems both c and d satisfies the condition..
• 8 years agoHelpfull: Yes(0) No(0)
• give any value for option c the sum number is ending with odd.so ans is c
• 7 years agoHelpfull: Yes(0) No(0)
• C and D (Original Answer given as D)
  You just remember the following odd ± odd = even; even ± even = even; even ± odd = odd
  Also odd × odd = odd; even × even = even; even × odd = even.
• 5 years agoHelpfull: Yes(0) No(0)
• b) is the right answer (m+n^2) (m-n^2)
• 2 years agoHelpfull: Yes(0) No(0)