Answer:
There are 65 goblins in the club
Step-by-step explanation:
Let number of goblins in the magic club be x
Number of goblins and wizards in the magic club = 120
So, Number of wizards in the magic club be 120 - x
So, Number of goblins = Number of wizards + 20% of number of wizards
⇒ x = 120 - x + 20% of (120 - x)
⇒ x = 120 - x + 0.2·(120 - x)
⇒ 2·x = 120 + 24 - 0.2·x
⇒ 2.2·x = 144
⇒ x = 65.45
Hence, Number of goblins in the magic club = 65