How did they get answer E?



14. If output is produced according to Q = 4l + 6k, (l is the quantity of L and k is the quantity of K) the price of K is $12, and the price of L is $6, then the cost minimizing combination of K and L capable of producing 60 units of output is

A. l = 5 and k = 6.66. B. l = 7.5 and k = 5.

C. l = 6 and k = 6. D. l = 0 and k = 10.

E.l = 15 and k = 0.