Outline Mathematics
Word Problems

Coin counting word problem

Here's a problem to tackle:

  There are 9 coins all together, some of them pennies, some nickels and some dimes. If you collect up all the pennies and nickels, there are 7. If you collect up all the nickels and dimes, there are 5. How many of the 9 coins are pennies, how many nickels, how many dimes?

Solution 1

Solution 2

Solution 3


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Copyright © 1996-2018 Alexander Bogomolny

Solution 1

  There are 9 coins all together, some of them pennies, some nickels and some dimes. If you collect up all the pennies and nickels, there are 7. If you collect up all the nickels and dimes, there are 5. How many of the 9 coins are pennies, how many nickels, how many dimes?

(In the applet below, click on the underlined omitted expressions. See what happens.)

// formulations

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at https://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.

Do not forget to check your solution.


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Copyright © 1996-2018 Alexander Bogomolny

Solution 2

  There are 9 coins all together, some of them pennies, some nickels and some dimes. If you collect up all the pennies and nickels, there are 7. If you collect up all the nickels and dimes, there are 5. How many of the 9 coins are pennies, how many nickels, how many dimes?

(In the applet below, click on the underlined omitted expressions. See what happens.)

// formulations

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at https://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.

Do not forget to check your solution.


|Contact| |Front page| |Contents| |Algebra|

Copyright © 1996-2018 Alexander Bogomolny

Solution 3

  There are 9 coins all together, some of them pennies, some nickels and some dimes. If you collect up all the pennies and nickels, there are 7. If you collect up all the nickels and dimes, there are 5. How many of the 9 coins are pennies, how many nickels, how many dimes?

(In the applet below, click on the underlined omitted expressions. See what happens.)

// formulations

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at https://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.

Do not forget to check your solution.

References

  1. S. Beckman, Mathematics For Elementary Teachers, Pearson Education, 2003

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Copyright © 1996-2018 Alexander Bogomolny

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