1,5,6,25,30,31....
find the 99th term of the series

• i think there will be 26 in between 25 and 30.
  2nd term =1st term *5(1*5=5)
  3rd term =2nd term +1(5+1=6)
  ie.
  12th term =5*6th term
  24th term =5*12th term
  48th term =5*24th term
  49th term =48th term+1
  98th term =5*48th term
  99th term =98th term+1
  hence ans is 18756
  
  
• 10 years agoHelpfull: Yes(7) No(8)
• 
  2nd term =1st term *5 ,i.e 1*5=5
  3rd term =2nd term +1 i.e 5+1=6
  4th term = 2nd term*5,i.e 5*5=25
  5th term = 4th term+1,i.e 25+1=26
  6th term = 3rd term*5,i.e6*5= 30
  .
  .
  .
  12th term =6th term*5
  24th term =12th term*5
  48th term =24th term*5
  49th term =48th term+1
  98th term =49th term*5
  99th term =98th term+1,i.e 18755+1=18756
  hence answer is 18756.
• 10 years agoHelpfull: Yes(5) No(0)
• It goes like let x be position of number in series.
  so
  for 1, x=1
  for 5, x=2
  for 6, x=3
  
  and element at x decided the (2*x)th and (2*x+1)th element.
  
  as 1 deides, 1*5, 1*5+1
  then 5 decides, 5*5,5*5+1
• 10 years agoHelpfull: Yes(0) No(5)
• plz xplain it..
• 10 years agoHelpfull: Yes(0) No(0)
• 
  1,5,6 ,25, 26,30,31, 125,126,130,131,150,151,155,156,………………
  
  1st term gives 2nd and 3rd term. .
  1st term* 5= 5(2nd term)
  2nd term +1=6(3rd term)
  multiply current position by 2 gives the position of term which is multiplied by no 5
  2nd term gives 4th and 5th term. .
  likewise check for others
  15th term gives 30th and 31st term. .
  ans:15th term*2=30th term
  so that 156*5=780(30th term)
  31st term is 780+1=781
• 10 years agoHelpfull: Yes(0) No(0)
• ans = -2,0,1,2
• 9 years agoHelpfull: Yes(0) No(0)