SOLUTION: The problem reads as follows. I have 90 coins in my piggy bank, all of which are nickels and dimes. When I count the money in the piggy bank, I find that I have $15.10. How many

Question 948058: The problem reads as follows.
I have 90 coins in my piggy bank, all of which are nickels and dimes. When I count the money in the piggy bank, I find that I have $15.10. How many nickels do I have and how many dimes do I have? Be sure to show all your work.
d+n= 90 d=90
0.05n +0.10d= $15.10
0.05+0.10 (90n)= 15.10
0.05n+ 9-0.10n= 15.10
0.05n-d0.10n=6.10
-0.05n=6.10
n=122
0.05 (90d) +0.10d= 15.10
4.5-0.05d+0.10d= 15.10
0.05d=10.6
d= 212
Found 2 solutions by josgarithmetic, MathLover1:
Answer by josgarithmetic(39625) (Show Source): You can put this solution on YOUR website!

Subtract the coin count equation from the money count (simplified) equation.
This is using the Elimination Method.

IMPOSSIBLE.

Check: If all coins were nickels, then coins.
If all coins were dimes, then coins.
Number of total coins given was 90.
-
If all 90 coins were nickels, dollars.
If they were all dimes, then 80 dollars.
Amount of money given was $15.10.

The problem description is wrong.

Answer by MathLover1(20850) (Show Source): You can put this solution on YOUR website!
something is wrong with this problem...are you sure there is coins, or $
if and , then coins, and

$
$
so, $ which is much more then $

but, when I try with $, it works

total coins :
........equation 1
total money: $
.....equation 2
from equation 1 we have:
.....equation 2....solve for

then

check:

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