If the Snowboard Industry Is Dominated by Four Large Firms

Multiple Choice

If the snowboard industry is dominated by four large firms, each with 20% market share, and two small firms, each with 10% market share, what is the four-firm concentration ratio and what is the Herfindahl-Hirschman Index (HHI) ?

A) four-firm concentration ratio = 60; HHI = 1,600
B) four-firm concentration ratio = 60; HHI = 1,800
C) four-firm concentration ratio = 80; HHI = 1,600
D) four-firm concentration ratio = 80; HHI = 1,800