Thank u, but im still abit confused.
how to get the 15 parts and 6unit?

Thank u, but im still abit confused.
how to get the 15 parts and 6unit?

There are 3 parts for pigs and 5 parts for goats initially. So we convert both to 15 parts. Hence, there are 5 units for pigs and 6 units - 54 for goats. Equate both together since both are converted to 15 parts and then solve.