Need help setting up an equation here: An all-day parking meter takes only dimes and quarters. If it contains 100 coins with a total value of $14.50, how many of each coin are in the meter?

Question

anonymous · Answer

Dimes and quarters are 10 cents and 25 cents respectively. Therefore we make the following statement, mathematically,

0.1d + 0.25q = 14.50

Where d represents the number of dimes, and q represents the number of quarters. But this equation is a single equation with two unknowns, therefore we need another equation to solve it. We know that the parking meter contains 100 coins, and we know that d and q represent the number of dimes and quarters therefore we state,

d+q = 100

Now we have two equations and two unknowns. Can you solve this system?