Show me how to solve these following questions in Excel Solver

SOLVER ANSWERS
2-a.	Unit sales required to attain a margin of safety percentage of 15%		units
2-b	unit sales required to attain a profit margin of 8%		units
2-c	selling price per unit required to attain a profit margin of 10%
2-d	Variable expense per unit required to attain a profit margin of 6%

This is the template:

Data Inputs:
Unit sales	40,000
Selling price per unit	$ 12.50
Variable expense per unit	$ 7.50	$ 5.00
Total fixed expenses	$ 180,000
Contribution Format Income Statement			Margin of Safety
	Total	Per Unit	%			Actual sales (a)	$ 500,000
Sales	$ 500,000	$ 12.50	100%			Break-even sales (b)	$ 450,000
Variable expenses	300,000	7.50	60%			Margin of safety in dollars (a) (b)	$ 50,000
Contribution margin	200,000	$ 5.00	40%			Margin of safety percentage	10.00%
Fixed expenses	180,000
Net operating income	$ 20,000
Net profit margin percentage	4.00%