There is only one gas station within hundreds of miles. The owner finds that when she charges $3 a gallon, she sells 199 gallons a day, and when she charges $2.99 a gallon, she sells 200 gallons a day. The marginal revenue of the 200th gallon of gas is:

Tara and her parents want to save at least $40,000 for college in 8 years. which statement describes the most effective savings plan for tara and her parents to meet their goal? tara and her parents should make deposits of $300 every month into a college savings account. tara and her parents should make deposits of $450 every month into a college savings account. tara and her parents should make deposits of $3,000 every year into a college savings account. tara and her parents should make deposits of $4,000 every year into a college savings account