Question

Let K is any three digit number which is perfect square and perfect cube both where k, 600 < K < 750 then what will be the sum of digits of K?
1. 18
2. 20
3. 17
4. 15

Answer 1

Correct Answer - Option 1 : 18

Given:

It is given that K is three digit number where k, 600 < K < 750

Calculation:

Let suppose the number is 9

∴ 9 × 9 × 9 = 729, perfect cube

Now, consider the expression again

∴ 9 × 9 × 9 = (9 × 3) × (3 × 9) = 27 × 27 = 729, perfect square

Now, sum of digits

∴ 7 + 2 + 9 = 18

Hence, option (1) is correct