Coin Collection

[lisamg9657]

How was this figured out when you do not know how many coins you have at the beginning for a different equation? I am trying to figure it out but come up blank at this time. the question is: A collection of nickels, dimes, and quarters consist of [FONT=MathJax_Main]120[/FONT] coins with a total of [FONT=MathJax_Main]$[FONT=MathJax_Main]13.00[/FONT][/FONT]. If there are [FONT=MathJax_Main]3[/FONT] times as many dimes as quarters, find the number of each type of coins. I use to know but now I am a blank. I know I need to practice more now. I am also having problems trying to find the community thread. I feel like a dunce right now.

 

[mmm4444bot]

Hi. You never commented on JeffM's reply, in your thread (coin equation) from a few days ago, on this very topic. Did you understand the equation, that Jeff posted for you?

If you missed his reply, there is info about subscribing to threads in the FAQ. That is, before you click the submit button on your thread, there is a checkbox option for receiving links by e-mail when people reply. You may also click the My Profile link, near the upper-right corner of the board pages; that should take you to a listing of your recent posts. Also, if you see your username anywhere, you may right-click it, to see a menu option for viewing your posts.

Can you take a guess at what this equation means?

n + d + q = 120

Please tell us, in your own words, and then we can go from there.

You have three unknown quantities to find, so you need to write a system of three equations (using the numbers n, d, and q), followed by solving the system. If you don't understand variable symbols, like n, d, and q, let us know. If you don't know how to solve by substitution or elimination, we can post a link to on-line videos that explain these basics.

Do you have experience solving single equations?

Please tell us what you already understand. We need to know where you are stuck.

 

[lisamg9657]

Coin equation

Hi mmm4444bot.,

As for your question as do I have Microssoft Office yes I do. So if you want to send an email with word you can. Thank you for your help.

lisamg9657

 

[mmm4444bot]

Hi mmm4444bot.,

As for your question as do I have Microssoft Office yes I do. So if you want to send an email with word you can.

I'm confused; I do not recall asking you about Microsoft Office. Was that in a different thread?

I do not send e-mail to members. :?

 

[HallsofIvy]

Let "N" be the number of nickels, "D" the number of dimes, and "Q" the number of quarters. Since you have 120 coins, this is N+ D+ Q= 120. Each nickel is worth $0.05 so N nickels is worth .05N dollars. Each Replacing dime is worth $0.10 so D dimes is worth .10D dollars. Each quarter is worth $0.25 so Q quarters is worth .25Q. The total value is .05N+ .10D+ .25Q and you are told this is "a total of [FONT=MathJax_Main]$[FONT=MathJax_Main]13.00" so .05N+ .10D+ .25Q= 13. Finally, "there are [FONT=MathJax_Main]3 times as many dimes as quarters" so D= 3Q. That gives you three equations to solve for N, D, and Q. [/FONT][/FONT][/FONT]