Question

What should come in place of question mark ‘?’ in the following number series?

500, 475, 426, 345, 224, ?

1. 51
2. 52
3. 53
4. 54
5. 55

Answer 1

Correct Answer - Option 5 : 55

Calculation:

Considering the above series,

500, 475, 426, 345, 224, ?

The logic of the series can be explained as,

500 – (5)² = 475

475 – (7)² = 426

426 – (9)² = 345

345 – (11)² = 224

By observing the pattern, we can write

224 – (13)² = 55

⇒ ? = 55

∴ The value of ? is 55