SOLUTION: I am having trouble figuring my math problem out. The problem is "Molly has $5.45 in coins. She has two more nickels than dimes. She has nine fewer quarters than dimes. How many of

Algebra.Com
Question 997320: I am having trouble figuring my math problem out. The problem is "Molly has $5.45 in coins. She has two more nickels than dimes. She has nine fewer quarters than dimes. How many of each coin does she have?"
Found 3 solutions by josgarithmetic, KMST, MathTherapy:
Answer by josgarithmetic(39618)   (Show Source): You can put this solution on YOUR website!
n nickels, d dimes, q quarters;



Divide the money equation by 0.05 and adjust the quarters equation.

Notice that the n and the q equations both are in terms of d.
..
..
You see what you can do?
Answer by KMST(5328)   (Show Source): You can put this solution on YOUR website!
You have to assume that Molly has no pennies, half-dollar coins, or dollar coins.
The problem does not tell you that, but maybe it should.

IF YOU STUDIED SYSTEMS OF LINEAR EQUATIONS:
You start by defining three variables:
= number of nickels Molly has,
= number of dimes Molly has, and
= number of quarters Molly has.
So,
$= amount of money that Molly has as nickels.
$= amount of money that Molly has as dimes.
$= amount of money that Molly has as quarters.
The half assumed fact that Molly has $5.45 in coins" between nickels dimes and quarters, with no pennies, half-dollars, or dollars, means that
is one of your equations.
"She has two more nickels than dimes" translates as the equation
.
"She has nine fewer quarters than dimes" translates as
.
With all 3 equations, you have the system
.
You can have a simpler system, if you simplify equation by
dividing both sides of the equal sign by , or
multiplying both sides of the equal sign times (same thing, really).
then you get , which is simpler.
The system or is easy to solve by substitution,
substituting for for in the first equation:
-->-->-->-->-->-->-->-->-->

IF YOU HAVE NOT STUDIED SYSTEMS OF LINEAR EQUATIONS:
You carefully choose one variable to define, so that you can calculate everything from that variable:
= number of dimes Molly has.
"She has two more nickels than dimes" means that
= number of nickels Molly has, and
"She has nine fewer quarters than dimes" means that
= number of quarters Molly has.
Then,
$= amount of money that Molly has as nickels,
$= amount of money that Molly has as quarters, and
$= $= amount of money that Molly has in coins.
Then you solve the equation
to find .
Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!

I am having trouble figuring my math problem out. The problem is "Molly has $5.45 in coins. She has two more nickels than dimes. She has nine fewer quarters than dimes. How many of each coin does she have?"
Let number of dimes be D

Then number of nickels = D + 2

Number of quarters = D - 9

We then get the value equation: .1D + .05(D + 2) + .25(D - 9) = 5.45

.1D + .05D + .1 + .25D - 2.25 = 5.45

.1D + .05D + .25D + .1 - 2.25 = 5.45

.4D - 2.15 = 5.45

.4D = 5.45 + 2.15

.4D = 7.6

D, or number of dimes = , or 

Number of nickels: 19 + 2, or 

Number of quarters: = 19 - 9, or  

RELATED QUESTIONS


I am having trouble figuring out how to deal with the Ned to figure out the 21 coins part  (answered by bucky)

Molly has a collection of coins worth $5.20. She has 8 more nickles than quarters. How... (answered by josmiceli)

Molly has 14.90 coins. she has two more nickels than dimes. she has eight fewer quarters... (answered by josmiceli)

I have a question I am having problem with.  This should be very simple I know. I am... (answered by Fombitz)

I have a question on my Algebra I homework. The question is," Lucy has some coins in her... (answered by ankor@dixie-net.com)

molly has $12.30 in coins. she has four more nickels than dimes. she has 6 fewer quarters  (answered by clarinetgirlM)

Molly has $15.05 in coins.

She has three more nickels than dimes.

She has six fewer  (answered by macston)

Molly has $18.40 in coins. She has three more nickels than dimes. She has seven fewer... (answered by jorel555)

Hi, I don't know how to do this word problem in my algebra class. We are supposed to use... (answered by mananth)