A student has a savings account earning 9% simple interest. She must pay $1500 for first-semester tuition by September 1 and $1500 for second-semester tuition by January 1. How much must she earn in the summer (by September 1) to pay the first-semester bill on time and still have the remainder of her summer earnings grow to $1500 between September 1 and January 1?

What is the difference between total utility and marginal utility? a. marginal utility is subject to the law of diminishing marginal utility while total utility is not. b. total utility represents the consumer optimum while marginal utility gives the total utility per dollar spent on the last unit. c. total utility is the total amount of satisfaction derived from consuming a certain amount of a good while marginal utility is the additional satisfaction gained from consuming an additional unit of the good. d. marginal utility represents the consumer optimum while total utility gives the total utility per dollar spent on the last unit.