can anyone help me answer this question please, its for 3rd year economics degree..:

Suppose an industry, with a contestable market structure, has an
incumbent firm and several potential competitors that all have identical
technologies summarised by the cost function TC=100+q2, where q is
the output of a firm. If the aggregate demand function facing the industry
is p = 60 – 4Q, where Q is the industrial output, solve for equilibrium
output and price for a contestable market.


thanks..