Bob's utility function is u(x1, x2) = 3x1 + x2, and he has income m = 10. The price of good 2 is p2 = 1. Let p1 denote the initial price of good 1, and let p1 denote a new lower price of good 1, so p1 < p1. (a) For what values (if any) of p1 and p1 is the substitution effect on good 1 equal to zero? (b) For what values (if any) of p1 and p1 is the income effect on good 1 equal to zero?