Question

Find out wrong number in the series 2, 3, 10, 38, 172​

Answer 1

Explanation:

The correct series would be: 2, 3, 10, 39, 172, 885, 5346.

The series starts with 2.

The next number is 3 = (2+1)*1

The next number is 10 = (3+2)*2

The next number is 39 = (10+3)*3

The next number is 172 = (39+4)*4

The next number is 885 = (172+5)*5

The next number is 5346 = (885+6)*6

So the ith number of the series, represented by a[i] is:

a[i]=(a[i−1]+(i−1))∗(i−1)

For example,

a[7]=(a[6]+6)∗6=(885+6)∗6=5346