Question - 6, 15, 35, 77, 165, 221
A. 35
B. 77
C. 165
D. 15
Answer -
Option C
Explanation:
The terms of the series are products of two consecutive prime numbers i.e. (2 x 3),
(3 x 5), (5 x 7), (7 x 11),.....
So, 165 is wrong and must be replaced by (11 x 13) i.e. 143.