What is the mean of a random variable that is uniformly distributed in [1/2,1] interval?
a) 1
b) 3/4
c) 0.5
d) cannot be determined without further information.

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?