One term in the number series is wrong. Find out the wrong term.
6, 15, 35, 77, 165, 221
A. 35
B. 77
C. 165
D. 15
Answer: Option C
Solution (By Examveda Team)
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.
This Question Belongs to Competitive Reasoning >> Series Completion
6*2 =12 + 3 = 15
15*2 = 30 +5 =35
35*2 =70 + 7 =77
77*2 = 154 +9 =163 so 165 is wrong .