In the series 3, 9, 15, ...... what will be the 21st term?

A. 117 B. 121
C. 123 D. 129

• C. 123
  
  series is an A.P. in which a = 3 and d = 6.
  Therefore 21st term = a + (21 – 1) d = a + 20d = 3 + 20 x 6 = 123.
• 12 years agoHelpfull: Yes(2) No(1)