Insert the missing number.

6.
2, 6, 12, 20, 30, 42, 56, (....)

A.
61
B.
64
C.
72
D.
70

• their difference makes a A.P series
  so on solving the ans is 72
• 13 years agoHelpfull: Yes(4) No(1)
• The series is +2 +4 +6 +8 +10 +12 +14 +16
  so 56+16 = 72
• 13 years agoHelpfull: Yes(3) No(2)
• the answer is c
  +4,+6,+8,+10,+12,+14,+16
• 13 years agoHelpfull: Yes(0) No(1)
• 2
  2*3=6
  2*6=12
  2*10=20
  2*15=30
  2*21=42
  2*28=56
  see the numbers which is multiplied with 2 ..... it's forming a series and series is +3,+4,+5 and so on...
  so next number is 2*36=72
• 11 years agoHelpfull: Yes(0) No(0)