Which one will replace the question mark ?

Answer: 1

Explanation: Each spoke is paired with the spoke directly opposite it, and one number is the square of the other. The pairs are:

• 2^2 = 4 (so 2 and 4 are opposite pair)

• 8^2 = 64 (so 8 and 64 are opposite pair)

• 5^2 = 25 (so 5 and 25 are opposite pair)

• 1^2 = 1 (so 1 and the missing number are opposite pair, hence the missing number = 1)