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A large pile of coins consists of pennies, nickels, dimes, and quarters. if the pile contains only 15 quarters and only 20 dimes but at least 30 of each other kind of coin, how many collections of 30 coins can be chosen?

User Amarildo
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2 Answers

6 votes

Final answer:

The problem requires calculating combinations of 30 coins from limited quarters (15) and dimes (20) and at least 30 pennies and nickels. We must consider possible distributions while adhering to the limitations, but an exact numerical answer cannot be provided without additional information on the total number of pennies and nickels.

Step-by-step explanation:

The student is essentially asking how many different combinations of 30 coins can be made when there are constraints on the number of quarters and dimes. To solve this, consider that there are only 15 quarters and 20 dimes, but at least 30 of each penny and nickel. If we are to make collections of 30 coins, we need to consider the possible distributions of those coins.

We can begin with the maximum number of quarters (15) since they are limited and subtract from there. For dimes, we can use up to 20. The remaining coins will be a mix of pennies and nickels which we have at least 30 of each and can be selected freely to reach the total of 30 coins per collection. We need to calculate combinations considering the restrictions on quarters and dimes.

Examples of combinations include:

  • 15 quarters, 15 pennies
  • 10 quarters, 20 dimes
  • 5 quarters, 20 dimes, 5 pennies

However, an exact number of combinations would require more detailed analysis to ensure we are not overcounting scenarios where there are more than 30 nickels or pennies available which could lead to duplicate counts. As it stands, the question cannot be solved numerically without more information about the total number of pennies and nickels.

User Amnon
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3 votes
Step-by-step explanation:

If the bank has only quarters and dimes, and its total amount of coins is 250, then be x the amount of quarters it has, it will have 250−x dimes.

A quarter is worth 0.25$, a dime is worth 0.10$ and the 250 coins together are worth 39.25$.

User Lucas Hendren
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6.7k points