9 coins. . The current coins (assuming US$) are 0.01, 0.05, 0.1, 0.25, 0.5 and 1 dollar You will need 4 * 1 dollarcent 1 * 5 dollarcent 2 * 10 dollarcent 1 * 25 dollarcent 1 * 50 dollarcent For a total of 9 coins.
f I have less than $1 in coins, what is the largest amount of money I could have and not be able to give someone exactly 50p?
What is the least number of coins required to have an exact change for all possible items that cost from one cent up to and including one dollar in one-cent increments?