Answer and Explanation:
The computation is shown below;
Given that
Price = P = $90
And, the Marginal cost = MC = $18
a.
Now the markup would be
= (P - MC) ÷ P
= ($90 - $18) ÷ $90
= $72 ÷ $90
= 0.80
= 80%
Now the monopoly markup is
b.
As we know that
Monopoly, markup = 1 ÷ elasticity of demand(e)
e = 1 ÷ markup
= 1 ÷ 0.8
= 1.25
The absolute value of e would always be negative so e = -1.25
Therefore
The firm s price elasticity of demand is -1.25
