SOLUTION: I have 30 coins consisting of 5c coins and 20c coins. If the total value of the coins is $3.45, how many coins do I have?

Question 945567: I have 30 coins consisting of 5c coins and 20c coins. If the total value of the coins is $3.45, how many coins do I have?

Found 2 solutions by kmanu, MathTherapy:
Answer by kmanu(1) (Show Source): You can put this solution on YOUR website!
Let x be the number of 5c coins
and y be the number of 20c coins
So we get the two equations as
x + y = 30 ........(1)
0.05x + 0.2x = $3.45 .........(2)
Multiplying equation (1) by -0.05 we get
-0.05x - 0.05y = -1.5 ..........(3)
Adding equation (1) and (3) we get
0.15y = 1.95
Dividing both sides by 0.15 we get
y = 13
Now put y = 13 in equation (1) we get
x + 13 = 30
Subtracting both sides by 13 we get
y = 17
So , you use 13 5c coins and 17 20c coins
Answer by MathTherapy(10552) (Show Source): You can put this solution on YOUR website!

I have 30 coins consisting of 5c coins and 20c coins. If the total value of the coins is $3.45, how many coins do I have?

Number of coins:
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