In the series 3, 9, 15,………….what will be the 21st term?
Table of Contents
A. 117
B. 121
C. 123
D. 129
Answer & Solution
Answer: Option C
Solution:
Clearly, 3 + 6 = 9, 9 + 6 = 15,………….
So, the series is an A.P in which a = 3 and d = 6
∴21st term = a + (21 – 1)d = a + 20d
= 3 +20 × 6 = 123.
Also Read:
- 1, 9, 25, 49, ?, 121.
- 4, 7, 12, 19, 28, ?
- 6, 11, 21, 36, 56, ?
- 10, 100, 200, 310, ?
- 8, 28, 116, 584, ?
- 3, 7, 23, 95, ?
- 7, 26, 63, 124, 215, 342, ?
- 165, 195, 255, 285, 345, ?
- 34, 45, 56, 67, ……. What number should come next?
- Find out the wrong number. 150, 450, 750, 1060,1350,1650,1950
