Question 224659: Jake has 205 coins consisting of nickels, dimes, and quarters. If the total value of the coins is $22 and there are three times as many dimes as nickels, how many of each coin did he have?
Answer by drj(1380) (Show Source):
You can put this solution on YOUR website! Jake has 205 coins consisting of nickels, dimes, and quarters. If the total value of the coins is $22 and there are three times as many dimes as nickels, how many of each coin did he have?
Step 1. Let x be the number of nickels.
Step 2. Let 0.05x be the dollar value of nickels.
Step 3. Let y be the number of dimes
Step 4. Let 0.10y be the dollar value of dimes.
Step 5. Let z be the number of quarters.
Step 6. Let 0.25z be the dollar value of quarters.
Step 7. Then x+y+z=205 since the total number of coins is 205.
Step 8. Then 0.05x+0.10y+0.25z=22 since the dollar value of nickels, dimes, and quarters is 22.
Step 9. We are also given y=3x since there are three times as many dimes as nickels.
Step 10. Here's our system of linear equations given in Steps 7, 8, and 9.
Equation A
Equation B
Equation C
Substitute Equation C into Equations A and B
or Equation A1
or Equation B1
Solved by pluggable solver: SOLVE linear system by SUBSTITUTION |
Solve:
We'll use substitution. After moving 1*z to the right, we get:
, or . Substitute that
into another equation:
and simplify: So, we know that z=25. Since , x=45.
Answer: .
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With and then
Check dollar value... ...which is a true statement.
Step 11. ANSWER: The number of nickels is 45, the number of dimes is 135, and the number of quarters is 25.
I hope the above steps were helpful.
For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.
Good luck in your studies!
Respectfully,
Dr J
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