the product of two number is 12960 and their hcf is 36. how many such pairs can be formed

HCF * LCM = Product of the two numbers => LCM = 12960/36 = 360
Let the two numbers be 36a and 36b, where 'a' and 'b' are coprime
LCM = 36ab = 360 => ab = 10
The possible pairs of numbers are (1, 10), (2, 5)
So, two pairs of numbers can be formed