Let g = HCF(x, y). Write x = g·d, y = g·h with gcd(d, h) = 1.
Then x·y·HCF(x, y) = (g d)(g h)g = g³ d h = 1080.Prime factorization: 1080 = 2³ · 3³ · 5.
For g³ | 1080, g can only use primes with exponents ≤ 1 (since exponents triple):
g ∈ {1, 2, 3, 6}.For each g, N = 1080 / g³ must be split as d·h with gcd(d, h) = 1.
If N has k distinct primes, the number of ordered coprime splits (d, h) is 2^k
(each prime-power goes wholly to d or to h).
g = 1 ⇒ N = 1080 (primes {2,3,5}, k=3) ⇒ 2³ = 8 ordered pairs
g = 2 ⇒ N = 135 = 3³·5 (primes {3,5}, k=2) ⇒ 4 ordered pairs
g = 3 ⇒ N = 40 = 2³·5 (primes {2,5}, k=2) ⇒ 4 ordered pairs
g = 6 ⇒ N = 5 (primes {5}, k=1) ⇒ 2 ordered pairs
Total ordered pairs = 8 + 4 + 4 + 2 = 18.
Since d ≠ h in all cases (N ≠ 1), unordered pairs = 18 / 2 = 9.
Hence, 9 pairs.
Hence the highest power of 30 in 50! = 12



