Directions (61-65) : Find the wrong number in following number series.

5 , 43 , 70 , 88 , 99 , 104, 108

The correct option is 104.

To find the wrong number in the given number series, let us calculate the difference between consecutive terms:

$43-5=38$

$70-43=27$

$88-70=18$

$99-88=11$

$104-99=5$

$108-104=4$

Now, let us examine the pattern of differences (second-order differences):

$38-27=11$

$27-18=9$

$18-11=7$

The second-order differences follow a pattern of decreasing odd numbers: 11, 9, 7, 5, 3.

Continuing this pattern for the remaining terms:

Next difference should be:
$11-5=6$

So, the 6th term should be:
$99+6=105$

Checking the last term with the next difference (6 - 3 = 3):

$105+3=108$

This matches the last term 108. Therefore, the wrong term in the series is 104, which should be replaced by 105.