The HCF of 2472, 1284 and a third number 'N' is 12. If their LCM is 23 × 32 × 5 × 103 × 107, then the number 'N' is:

Answer: Option D

We have,
HCF of the numbers × LCM of the numbers = Multiplication of the numbers.
(12) × (2³ × 3² × 5 × 103 × 107) = 2472 × 1284 × N
Hence,
N = $$\frac{\{\left(12\right)\times \left(2^3\times 3^2\times 5\times 103\times 107\right)\}}{2472\times 1284}$$
Or, N = 3 × 5