Fill the missing number in the given figure?

26

The correct answer is Option (1) → 26

Look at the numbers in order:

• $5 = 2^2 + 1$
• $10 = 3^2 + 1$
• $? = 5^2 + 1$
• $50 = 7^2 + 1$
• $122 = 11^2 + 1$

Here, the bases 2, 3, 5, 7, 11 are prime numbers, and each sector contains:

$(\text{prime})^2 + 1$

So the missing value is:

$5^2 + 1 = 25 + 1 = 26$