Donna de paul is working to raise money for the homeless by sending information letters and making follow-up calls to local labor organizations and church groups. she discovers that each church group requires 2 hours of letter writing and 1 hour of follow-up, while for each labor union she needs 2 hours of letter writing and 3 hours of follow-up. donna can raise $100 from each church group and $200 from each union local, and she has a maximum of 16 hours of letter-writing time and a maximum of 12 hours of follow-up time available per month. determine the most profitable mixture of groups she should contact and the most money she can raise in a month.