In the following question, select the missing number from the given series.

64, 72, 45, 109, -16, ?

a) 205
b) 180
c) 200
d) 208

Ans : c) 200

SSC Constable GD Reasoning – 23 Feb 2024 paper

Solution :

We need to identify a pattern to find the missing number.
Let’s look at the differences between consecutive numbers:

• Difference between 72 and 64: 72−64=8
• Difference between 45 and 72: 45−72=−27
• Difference between 109 and 45: 109−45=64
• Difference between -16 and 109: −16−109=−125

Difference :
+8 (2³), -27(3³), +64(4³), -125(5³),
Next difference will be +6³ = 216

Next number – missing number from the given series is -16+216 =200