Ben spends $50 a year on 2 bunches of flowers and $50 a year on 10,000 gallons

Question:

Ben spends $50 a year on 2 bunches of flowers and $50 a year on 10,000 gallons of tap water. Ben is maximizing utility and his marginal utility from water is 0.5 unit per gallon.
a. Are flowers or water more valuable to Ben?
b. Explain how Ben’s expenditure on flowers and water illustrates the paradox of value.