Are you sure that's the entire question? If it is, return to sender. As it stands the question has no answer. You can arbitrarily determine its truthiness. Even your gut feeling would be a valid argument.
Can you think of why there is no answer? What does 12/c<sup>2</sup> mean? What does 12/c mean? What is the connection between the two? What is the inference you are trying to establish?
I've placed some numbers in for c and c^2 to see if it works. But i do not get the wordin of the question. i would believe any value of c would work except zero.