Answer:
The number of
Dimes = d = 20 dimes
Quarters = q = 10 quarters
Step-by-step explanation:
Let us represent
The number of :
Dimes = d
Quarters = q
Note that:
A dime is worth 10 cents = 0.10d
A quarter is worth 25 cents = 0.25q
A Wonsan has 30 coins in her pocket, all of which are dimes and quarters .
d + q = 30...... Equation 1
d = 30 - q
If the total value of the coins is $4.50
0.10d + 0.25 q = 4.50.....Equation 2
We substitute 30 - q for d in Equation 2
0.10(30 - q) + 0.25q = 4.50
3 - 0.10q + 0.25q = 4.50
- 0.10q + 0.25q = 4.50 - 3
0.15q = 1.5
q = 1.5/0.15
q = 10 quarters
Solving for d
d = 30 - q
d = 30 - 10
d = 20 dimes
Therefore:
The number of
Dimes = d = 20 dimes
Quarters = q = 10 quarters
