a parking meter contains quarters and nickels worth $7.25. There are 69 coins in all. How many quarters and how mant nickels are there?

Question

anonymous · Answer

Call the number of quarters 'q', and the number of nickels 'n'. The total number of all coins is 69, and the total value of quarters and nickels (number of quarters times value of quarters + number of nickels times value of nickels) is $7.25. That gets you two equations, and two variables!

mathmate · Answer

calculation error corrected. Assume all nickels, you get 3.45. Change (7.25-3.45)/0.20=19 for quarters. That gives you 69-19=50 nickels and 19 quarters.