Question

Q. Find the missing number in the following series?

3, 5, 5, 19, 7, 41, 9, ?

A) 71
B) 61
C) 79
D) 69​

Answer 1

Answer:

The answer is A) 71

Step-by-step explanation:

The odd terms of the sequence are 3,5,7,9 ,………

even terms are 5,19,41……..

5=(3*2)-1.

19=(5*4)-1

41=(7*6)-1

The rule to find an even term is [{preceding term*(preceding term-1)}-1]

Or equivalently

When n is even

nth term={(n+1)n}-1

Hence the next term which is 8 th term =9*8–1=71