Look at the figure below:

What is the length, in units, of segment CD?

200 greeting cards must be sold in order to achieve the breakeven. By seeling 200 greeting cards the company will be in position of no profit and loss position.

Explanation:

The breakeven point could be found from the following formula:

Breakeven Point = Fixed Cost / Contribution per unit Eq 1

Here

Contribution per unit = Selling Price - Variable Cost

Contribution per unit = $3 - $1 = $2 per unit

Putting values in the equation 1, we have:

Breakeven Point = $400 / $2 per unit = 200 units