What is 87th term in series:
2.10.26.50?

ans-3741

• 2=1^2+1
  10=3^2+1
  26=5^2+1
  ..........
  here ,1,3,5,7...... are odd numbers so by using An=a+(n-1)d
  we can find the A87 th term for odd no. series..
  A87=1+(87-1)x 2= 173
  so ,the 87th term will be...
  173^2+1=29930
  
  ans: 29930
• 8 years agoHelpfull: Yes(20) No(3)
• as per the given series
  Tn=T(n-1) +8*(n-1)
  T87= T86+ 8*86
  T87=2+8*(1+2+3............86)
  T87= 2+8*(86*87/2)
  T87=2+3741
  T87=3743
  
  
• 8 years agoHelpfull: Yes(7) No(5)
• Consider the AP 0,8,16,24,,...........87th term is 688
  a = 0
  d=8
  t87 = 87/2 ( 2(0)+(86)8) = 29928
  as series starts from 2
  add 2
  answer is 29928 + 2 = 29930
• 5 years agoHelpfull: Yes(2) No(0)
• ans is 2066
  
• 7 years agoHelpfull: Yes(0) No(1)
• -->The difference b/w each num= Multiples of 8.
  The nth term of the main series can be expressed as :
  
  2 + sum of the series 8, 16, 32… till (n-1) terms
  
  2 = 2+0
  10 = 2+ 8
  26 = 2 + 24 = 2 + (8 +16)
  50 = 2 + 48 = 2 + (8 + 16 + 24)
  .
  ..
  nth term = 2 + (8+16+24+ ...+ till (n-1))
  Therefore, the sum of 8, 16, 32… till (n-1) using the formula for the sum of an arithmetic progression will be
  
  S=n−12[16+(n−2)8]
  
  This simplifies as,
  
  4n(n−1)
  Thus the general term of the main series will be,
  
  Tn=2+4n(n−1)
  
  .
  
  .
  
  Thus the 87th term is
  
  T87=2+4×87×86
  
  T87=29930
• 5 years agoHelpfull: Yes(0) No(0)