2021 JMPSC Sprint Problems/Problem 2


Brady has an unlimited supply of quarters ($0.25), dimes ($0.10), nickels ($0.05), and pennies ($0.01). What is the least number (quantity, not type) of coins Brady can use to pay off $$2.78$?


It is generally best to use the smallest number of coins with the most value, specifically the quarters, for taking away a big chunk of the problem. We are able to fit $11$ quarters, or $$2.75$ into $$2.78$. That only leaves $3$ cents. We cannot put any nickels nor dimes, therefore we require three pennies to get a total of $$2.78$.

The least number of coins Brady can use to pay off $$2.78$ will be $14$ coins.


Solution 2

You want as many quarters in order to cut down on the number of coins. The most amount of quarters you can have is $11$. Since you can't use three cents on anything other than pennies, the remaining coins are $3$ pennies. Therefore $11+3=14$

- kante314 -

See also

  1. Other 2021 JMPSC Sprint Problems
  2. 2021 JMPSC Sprint Answer Key
  3. All JMPSC Problems and Solutions

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