$(8$ Points$)$ Short Answers

a$)(2$ points$)$ If a transportation problem has $12$ suppliers and $6$ demand locations, how many constraints does the problem have?

b$)(2$ points$)$ What does a shadow price that is zero mean for the constraint?

c$)(2$ points$)$ What programming mistake is responsible for $95\%$ of the non$-$integer answers in AGEC $217?$

d$)(2$ points$)$ If a variable has a reduced cost of zero, what can you say about that variable?