Question

A parking machine contained $3.05 made up of dimes and quarters. there were 20 coins in all. how many dimes were there?

Answer 1

1 dime = $0.10

1 quarter = $0.25

If we have x dimes, then we have (20-x) quarters.

x*0.1 + (20-x)*0.25 = 3.05

0.1x + 5 - 0.25x = 3.05

0.25x - 0.1x = 5 - 3.05

0.15x = 1.95

x = 1.95/0.15

x = 13 - number of dimes

Answer 2

Let's assume the number of dimes as 'd' and the number of quarters as 'q'.

We can form two equations based on the given information:

1. The total value of the coins is $3.05: 0.10d + 0.25q = 3.05

2. The total number of coins is 20: d + q = 20

To solve these equations, we can use substitution or elimination method. Let's use the substitution method in this case.

From the second equation, we have: d = 20 - q

Substituting this value in the first equation: 0.10(20 - q) + 0.25q = 3.05

Simplifying the equation: 2 - 0.10q + 0.25q = 3.05 0.15q = 3.05 - 2 0.15q = 1.05 q = 1.05 / 0.15 q = 7

Now that we know the number of quarters is 7, we can substitute this value back into the second equation to find the number of dimes: d + 7 = 20 d = 20 - 7 d = 13

Therefore, there are 13 dimes in the parking machine.