What will come in place of question mark '?' in the given number series?
3, 4, 5, ?, 13, 84, 85
Given series are Pythagorean triplets such that, the third term of one triplet is the first term of another triplet
⇒ 5, a and 13 are Pythagorean triplet
⇒ 52 + a2 = 132
⇒ 25 + a2 = 169
∴ a = 12