Answer:
b. 16 utils.
Explanation:
price of one apple = $0.75
marginal utility from consuming one apple = 24
utils per dollar (from apples) = 24 / $0.75 = 32 utils per dollar
since each banana costs $0.50, Hugh must be obtaining a marginal utility = 32/$ x $0.50 = 16 utils from one banana
when you maximize your marginal utility, the utils per dollar must be equal for both products