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Comments (3)
A
aloo_samosa
SSCBS
•5mos
Aapko pura solution samajh nahi aaya ya some part of it?
Let me know and I will try to explain it in a more simple way.
1
D
devesh
OP•5mos
no no thanks got it solution
1
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let x = d·a and y = d·b where gcd(a, b) = 1
then
x·y·gcd(x,y) = (d·a)(d·b)(d) = d³ab = 1080
so we need d³ab = 1080
prime factorize:
1080 = 2³ · 3³ · 5
now distribute powers between d³ and ab
since d³ has powers in multiples of 3, possible d:
d = 1, 2, 3, 6
now for each d, compute ab = 1080 / d³
d = 1 → ab = 1080 = 2³·3³·5 → primes = 3 → unordered coprime splits = 2^(3−1) = 4
d = 2 → ab = 1080 / 8 = 135 = 3³·5 → primes = 2 → ways = 2^(2−1) = 2
d = 3 → ab = 1080 / 27 = 40 = 2³·5 → primes = 2 → ways = 2
d = 6 → ab = 1080 / 216 = 5 → primes = 1 → ways = 1
total = 4 + 2 + 2 + 1 = 9
answer = 9
you got 4 because you probably only counted the d = 1 case and missed the other possible gcd values