What is the utility function u(t,z) given the prices of a day trip (t) and a pizza dinner (z)?
a) u(t,z) = t(1/4)z(3/4)
b) u(t,z) = t(3/4)z(1/4)
c) u(t,z) = t(1/3)z(2/3)
d) u(t,z) = t(2/3)z(1/3)