Please help!! Compute break$-$even point in units.

Review $22-4.$ Wales Company makes radios that sell for $$30$ each. For the coming year, management expects fixed costs to total $$200,000$ and variable costs to be $$20$ per unit.

$($a$)$ Compute the break$-$even point in dollars using the contribution margin $($CM$)$ ratio.

$($b$)$ Compute the margin of safety percentage assuming actual sales are $$750,000.$

$($c$)$ Compute the sales required in dollars to earn net income of $$120,000.$

Unit Selling Price $-$ Unit Variable Costs $=$ Contribution Margin Per Unit

$$30-$$$20=$$$10$

Contribution Margin per Unit $/$ Unit Selling Price $=$ Contribution Margin Ratio

Fixed Cost $/$ Contribution Margin per Unit $=$ Break$-$even Point in Units

Fixed Costs $\frac{?}{?}$ Contribution Margin Ratio $=$ Break$-$even Point in Dollars

Actual $($Expected$)$ Sales $-$ Break$-$Even Sales $=$ Margin of Safety in Dollars

Margin of Safety in Dollars $/$ Actual $($Expected$)$ Sales $=$ Margin of Safety Ratio