You can put this solution on YOUR website! Impossible. Suppose we have 5 pennies. Then we need two coins to total 25 cents, which we cannot do (assuming we use nickels, dimes, quarters). Now suppose we have no pennies. Then each coin must be worth at least a nickel, so the value of the coins is at least 35 cents (also a contradiction). Note that we cannot use 1, 2, 3, or 4 pennies because the total amount of money is divisible by 5.
