Well, for number 1, the minimum is of course attained if the 15 who are not married, 30 who have no cell phone, 25 who have no car and 20 who don't have a house are not overlapping at all. 15+30+25+20=90 who lack one of these 4 attributes. So 10 is the smallest possible number who has all 4. And it's good to see that bachelors have their priorities straight. Every bachelor in town owns his home, his car, and isn't on his parents' cell phone plan. Such an independent lot.
Number 2 looks like a toughie though.