Q. In a certain code if 64 is written as 343 and 216 is written as 729, then how is 512 written in that code?

Explanation : 

1. Observe that
64 = 4³ and its code 343 = 7³
216 = 6³ and its code 729 = 9³

2. In each case the cube‐root is increased by 3:
4 → 7 (4 + 3 = 7)
6 → 9 (6 + 3 = 9)

3. Apply the same rule to 512:
512 = 8³
Increase 8 by 3 → 11
Cube it → 11³ = 1331

Hence, 512 is written as 1331.