Given:
Total number of coins (Quarters and dimes) = 60
Total amount = $12.45
To find:
The number of quarters and dimes.
Solution:
Let x be the number of quarters and y be the number of dimes.
We know that,
1 quarter = 0.25 dollar
1 dime = 0.10 dollar
Total coins:
...(i)
Total amount:
...(ii)
From (i), we get
...(iii)
Putting this value in (ii), we get
![0.25x+0.10(60-x)=12.45](https://img.qammunity.org/2022/formulas/mathematics/college/80p9r7e0in9ct49iu3f9y7a3zb30oly20b.png)
![0.25x+6-0.10x=12.45](https://img.qammunity.org/2022/formulas/mathematics/college/tmss0bijb6kjxu2r3eneu6k4nb70dbghtq.png)
![0.25x-0.10x=12.45-6](https://img.qammunity.org/2022/formulas/mathematics/college/omqzk8snlroxt4ej3iuy6nk4q7ht3wm0jt.png)
![0.15x=6.45](https://img.qammunity.org/2022/formulas/mathematics/college/6ts2rjptgh13omryrm4x2cef9lzu83tin9.png)
Divide both sides by 0.15.
![x=(6.45)/(0.15)](https://img.qammunity.org/2022/formulas/mathematics/college/e4x5obgj3s6rl5s81lre4kn5qvm2bt1ds4.png)
![x=43](https://img.qammunity.org/2022/formulas/mathematics/college/i0507d4p27v0ykjzw4pm66hqv5btxahk7b.png)
Putting x=43 in (iii), we get
![y=60-43](https://img.qammunity.org/2022/formulas/mathematics/college/k6eqtdo5aq1fk87yv1dq3azefgsv5n7dfx.png)
![y=17](https://img.qammunity.org/2022/formulas/mathematics/college/zr4v14kw8i0a9g6puhvpd0hazk8sx8vzm8.png)
So, the number of quarters is 43 and the number of dimes is 17.
Therefore, the correct option is b.