iii) C = 3^7 × 5^2 × 7 Ck = (3^7 × 5^2 × 7) × k B/c Ck should be a product that is a perfect cube, the powers of the products should be divisible by 3. (3^7 × 5^2 × 7) × k = 3^9 × 5^3 × 7^3
k = (3^9 × 5^3 × 7^3) / (3^7 × 5^2 × 7) k = 3^(9-7) × 5^(3-2) × 7^(3-1) k = 3^2 × 5 × 7^2