If Carlos has 9 nickels and quarters in his pocket, and they have a combined value of 125 cents, how many of each coin does he have?

Answer 1

Let Carlos have n nickels. Then, he has 9 - n quarters. A nickel is worth 5 cents and a quarter is worth 25 cents. For his combination of coins, his value is 125 cents. Mathematically, this is expressed as

5(number of nickels) + 25(number of quarters) = 125

5n + 25(9-n) = 125

5n - 25n + (25)(9) = 125

-20n + 225 = 125

-20n = -100

20n = 100

n = 5

So, Carlos has 5 nickels and 9 - 5 = 4 quarters.