consider sequence 1,-2,3,-4,5,-6...what is average of first 200 terms?

• 1,-2,3,-4,5...=-1,-1,-1...100times
  -100/200=-0.5
• 9 years agoHelpfull: Yes(3) No(1)
• Sum of first n odd nos. = n^2 i.e. 100^2 in this case
  Sum of first n even n0. = n(n+1) = -10100 in this case
  avg= (-10100+10000)/200 = -0.5
• 9 years agoHelpfull: Yes(3) No(1)
• 1+3+5+..100 terms = 10000, -2+-4+-6+...100 terms = -10100, total = -100, avg=-100/200 = -.5
• 9 years agoHelpfull: Yes(2) No(1)
• sum of n odd numbers=n^2
  sum of n even numbers=n(n+1)
  odd numbers=1,3,5,7.............
  even numbers=2,4,6,8...........
  (100^2-100(100+1))/200=0.5
• 9 years agoHelpfull: Yes(1) No(1)
• 1-+3-4+5-6+7-8+9-10=-5
  -5/10= -0.5
• 9 years agoHelpfull: Yes(1) No(0)
• its in A.P i.e a+(n-1)d
  for odd num sum we get 199
  for even 200
  avg=(199-200)/2=-.5
• 9 years agoHelpfull: Yes(1) No(0)
• sum of any two terms i.e. 1+(-2)=3+(-4)=-1
  add this 100 times which gives sum of first 200 terms = -100
  AVG= sum/n
  -100/200=-0.5
• 9 years agoHelpfull: Yes(0) No(1)
• all d no gives some -100 so
  avg will be -100/200= -.5
• 9 years agoHelpfull: Yes(0) No(1)
• 1+3+5+.... =10000, -2-4-6....=-10100
  10000-10100=-100
  -100/200=-.5
• 9 years agoHelpfull: Yes(0) No(1)
• Add each pair. Hence we get -1*-1*-1*......100times=-100
  so avg is -100/200=0.5
• 9 years agoHelpfull: Yes(0) No(1)
• -100/200=-0.5
• 9 years agoHelpfull: Yes(0) No(1)
• take first 2 terms => 1-2 = -1
  next two terms => 3-4 = -1
  like that 100 pairs are there.so,total sum = -100
  => average = -100/200 =-0.5
• 9 years agoHelpfull: Yes(0) No(0)