Yoram insists on consuming 3 times as much y as he consumes of x (so he always has y = 3x). He will consume these goods in no other ratio. The price of x is 2 times the price of y. Yoram has an endowment of 24 x's and 42 y's which he can trade at the going prices. He has no other source of income. What is Yoram's gross demand for x?