1-2,2-3,3-4.....-98+99=???

• the ques is wrong
  (1-2)+(2-3)+(3-4)+.......+(97-98)+99=???
  1-2=-1
  2-3=-1
  similarly we get -1 97times.
  -97+99=2(ans)
  
• 11 years agoHelpfull: Yes(48) No(10)
• @Anand
  -1 we will get 49 times not 97 times.
  So answer will be -49+99=50(ans)
• 11 years agoHelpfull: Yes(15) No(21)
• Infact the original question is
  1-2+3-4+5-6+......-98+99=? for which 50 will be the ans.
• 11 years agoHelpfull: Yes(11) No(2)
• Since the question is wrong then the answer needs to be 2.
• 11 years agoHelpfull: Yes(5) No(1)
• -1-1-1-1..........97times + 99=2
• 11 years agoHelpfull: Yes(3) No(3)
• 100
  sum of 1+2+3+.....99
  and sum of -2-3-4-5-.....-98
  so the diff is 100
  
• 11 years agoHelpfull: Yes(3) No(4)
• there must b '+' instead of ',' i.e., the ques must be 1-2+2-3+3-4.....-98+99
  then all the no.(s) except 1,-98 and 99 will be cancelled out and the final expression will be like
  1-98+99
  = -97+99
  =2(ANS)
  
• 11 years agoHelpfull: Yes(3) No(2)
• 100 will be answer
  all numbers will be cancelled except 1 and 99
  on addition of 1 & 99 we get 100
• 11 years agoHelpfull: Yes(2) No(5)
• (1-2)+(2-3)+(3-4)+..........+(97-98)+99
  in this expression all the terms except 1,-98 and 99 will be omitted.
  so ans is 1-98+99=2
• 11 years agoHelpfull: Yes(2) No(2)
• qn is
  1-2+3-4+5-6+......-98+99
  =(1+3+5+...+99)-2(1+2+3+...+49)
  =50^2-49(49+1)
  =50(50-49)
  =50
  
• 11 years agoHelpfull: Yes(2) No(0)
• (1-2)+(2-3)+(3-4)+.......+(97-98)+99
  -49+99 = 50 ans.
• 11 years agoHelpfull: Yes(2) No(1)
• 1-2+2-3+3.....-97+98-98+99
  all cancels except 1 and 99
  so ans is 1+99= 100
• 11 years agoHelpfull: Yes(1) No(2)
• Ans is 100
  There are two APs
  First one is from 1-99 with a common difference of 1
  and second one is from -2 to -98 with common difference 1
  sum of the first one is 99*50
  sum of the second one is 97*50
  therefore, 99*50-97*50=100
• 11 years agoHelpfull: Yes(1) No(2)
• (1-2)+(2-3)+(3-4)+......(97-98)+99=-(98-1)+99=2(ans)
• 11 years agoHelpfull: Yes(1) No(0)
• oks
  may be
• 11 years agoHelpfull: Yes(0) No(1)
• @chandan...it will 49 times if the series be..:
  1-2,3-4,5-6,.....-98+99
• 11 years agoHelpfull: Yes(0) No(1)