Barnes Company reports the following for its product for its first year of operations.

Direct materials	$ 32	per unit
Direct labor	$ 22	per unit
Variable overhead	$ 10	per unit
Fixed overhead	$ 60,000	per year
Variable selling and administrative expenses	$ 2	per unit
Fixed selling and administrative expenses	$ 29,000	per year

The company sells its product for $120 per unit. Compute contribution margin using variable costing assuming the company (a) produces and sells 3,000 units and (b) produces 4,000 units and sells 3,000 units.