Which number should come next in the series 1, 3, 6, 10, 15,

D. 21
C. 24
B. 11
A. 8

• 21,,,,diff b/w 3-1=2
  6-3=3
  10-6=4
  15-10=5
  21-15=6
  so ansr=21
• 10 years agoHelpfull: Yes(2) No(0)
• 1+2=3
  3+3=6
  6+4=10
  10+5=15
  15+6=21
  Ans: 21
  
• 10 years agoHelpfull: Yes(1) No(0)
• 21 is ans
  1+2=3
  3+3=6
  6+4=10
  10+5=15
  15+6=21
• 10 years agoHelpfull: Yes(0) No(0)