Two series are 16,21,26 ?. and 17,21,25 ?..
What is the sum of first hundred common numbers

• the first series continues as 16,21,26,31,36,41,46,51,56,61,66,71,76,81, etc and thew second series goes as 17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,etc.. here the common terms are 21,41,61,81 and so on.. therefore
  21+41+61+81+....... till 100th term,
  so the 100th term is found by,
  t(100th term)=a+(n-1)d=21+(100-1)20=2001 , which is the 100th term
  now 21+41+61+81+.....+2001 = 100/2(21+2001)=10110, which is the required answer
• 10 years agoHelpfull: Yes(25) No(10)
• the ans is 101100
  first series 16,21,26.. with difference 5
  second series 17,21,25.. with difference 4
  5 and 4 LCM is 20.. thus the series is 21,41,61..
  sum= (n/2)*(2a+(n-1)d)
  =(100/2)*(42+(99*20))
  =50*2022
  =101100
• 10 years agoHelpfull: Yes(12) No(0)
• first series: 16,21,26,31,36,41,46,51,56,61,66,71,76,81, etc and
  second series: 17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81,etc..
  here the common terms are 21,41,61,81 and so on..
  21+41+61+81+....... till 100th term,
  so the 100th term is found by,
  t(100th term)=a+(n-1)d=21+(100-1)20=2001 =>100th term
  now 21+41+61+81+.....+2001 = 100/2(21+2001)=101110
• 10 years agoHelpfull: Yes(3) No(4)
• the common numbers is 21,41,61,81...and answer is 204
• 10 years agoHelpfull: Yes(0) No(7)