Two merchants agree that cows are worth $360 and that sheep are worth $240. When one merchant owes the other money, he pays the debt in cows or sheep, with "change" received in the form of sheep or cows as necessary. (For example, a $480 debt could be paid with two sheep, with one cow received in change.) What is the amount of the smallest positive debt that can be resolved in this way?
60
80
100
120
150
