For a telephone survey, a marketing research group needs to contact at least 150 wives, 120 husbands, 100 single adult males, and 110 single adult females. It costs $2 to make a daytime call and (because of higher labor costs) $5 to make an evening call. The table below lists the results. Because of limited staff, at most half of all phone calls can be evening calls.
% Daytime %Nighttime
Wives 30 30
Husbands 10 30
Single male 10 15
Single female 10 20
None 40 5
How many constraints are there? How many are <=? How many are >= (not including trivial)?