SOLUTION: Kathryn put her nickels and dimes in a piggy bank. One day she emptied it and counted 25 coins, which totaled $2.05. Using a linear system, how many dimes did Kathryn have?

Algebra ->  Customizable Word Problem Solvers  -> Coins -> SOLUTION: Kathryn put her nickels and dimes in a piggy bank. One day she emptied it and counted 25 coins, which totaled $2.05. Using a linear system, how many dimes did Kathryn have?      Log On

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Question 1005063: Kathryn put her nickels and dimes in a piggy bank. One day she emptied it and counted 25 coins, which totaled $2.05. Using a linear system, how many dimes did Kathryn have?
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
n+d= 25 subtract n from both sides:
d= 25-n We will use this value for d in the next equation
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0.05n+0.1(25-n)= 2.05
0.05n+2.5-0.1n= 2.05
-0.05n= -0.45 Divide both sides by -0.05 and remember that -/-=+:
n= 9 You have 9 nickels and:
25-9= 16 dimes
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Proof:
9(0.05)+16(0.10)= 2.05
0.45+1.60= 2.05
2.05= 2.05 We have the correct answer