Question

What will come in the place of question mark (?) in the following number series?

300, 297, 285, 263, 230, ?

1. 185
2. 187
3. 186
4. 200
5. 270

Answer 1

Correct Answer - Option 1 : 185

Given:

300, 297, 285, 263, 230, ?

Calculation:

From the above series, the logic can be explained as

300 - 297 = 3

297 - 285 = 12

285 - 263 = 22 

263 - 230 = 33

230 - ? = let's say x

Taking the double difference

12 - 3 = 9

22 - 12 = 10

33 - 22 = 11

By observing the pattern of double difference we can say

x - 33 = 12

⇒ x = 45

So, 230 - ? = 45

⇒ ? = 185

∴ The value of ? will be 185.