minus 1 divided by the price elasticity of demand (-1/Ed); the larger the number the lower the degree of monopoly power.
minus 1 divided by the price elasticity of demand (-1/Ed); the larger the number the greater the degree of monopoly power.
the markup ratio of price minus marginal cost to price, or (P-MC)/P; the larger the number the greater the degree of monopoly power.
Both 2 and 3.