Question

In the following number series, a wrong number is given. Find the wrong number.
3, 10, 24, 54, 108, 220, 444

• A. 108
• B. 10
• C. 24
• D. 54
• E. 220

Answer 1

The correct option is D 54

10 = 2 $\times$ 3 + 4
24 = 2 $\times$ 10 + 4
54 = 2 $\times$ 24 + 6
108 = 2 $\times$ 54 + 0
220 = 2 $\times$ 108 + 4
444 = 2 $\times$ 220 + 4
Pattern is disturbed at 3rd and 4th stages.
$\therefore$ 54 is wrong and should be replaced by 2 $\times$ 24 + 4
= 52. With this choice at 4th stage, 108 = 2 $\times$ 52 + 4 which follows pattern.