Need problem solved on Excel worksheet

A political candidate wants to use mass mailing to counteract some negative remarks made recently by her opponent. Our candidate has identified five mailing lists that contain names and addresses of voters she might like to reach. Each list can be purchased for a price. Partial lists are not for sale. The number of names on each list in each of four professional categories are listed below along with the desired number of names to reach in each category and the price of each list. Find the subset of lists that will provide the desired coverage at minimum cost.

List	Law	HealthCare	Bus. Execs.	Academe	Price
1	28	4	7	2	$41,000
2	9	29	11	3	$52,000
3	6	3	34	18	$61,000
4	2	4	6	20	$32,000
5	8	9	12	14	43,000
Desired coverage	20	18	22	20