Question 622173: a piggy bank contains only quarters and nickels and there is a total of 60 coins. The total value of coins is $7.40 Answer by math-vortex(648) (Show Source):
You can put this solution on YOUR website! Hi, there--
.
A piggy bank contains only quarters and nickels and there is a total of 60 coins. The total value of coins is $7.40
.
I'm guessing that you want to know the number of dimes and the number of nickels.
.
Let q be the number of quarters
Let n be the number of nickels.
.
There are 60 coins all together, so
.
We know that the value of the coins is $7.40. The quarters are worth .25 *d and the nickels are worth .05*n, so
.
We have a system of equations. We'll solve it using substitution to find the value of d and n.
.
Rewrite the first equation in terms of n.
.
.
Substitute 60-n for q in the second equation.
.
Simplify by combining like terms and solve for n.
-.20n=-7.60}}}
.
In the context of this problem, n=38 means that there are 38 nickels. Since the total number of coins is 60, there are 60-38=22 quarters.
.
Let's check to make sure that this number of quarters and nickels total $7.40. Twenty-two quarters is $5.50. 38 nickels is $1.90. It is true that $5.50+1.90=$7.40. Check!
.
That's it! Feel free to email if any part of this doesn't make sense yet.
.
Ms.Figgy
math.in.the.vortex@gmail.com
