Question

Giuliana has 22 quarters and dollar coins worth a total of $10.75.

Which equation can be used to find d, the number of dollar coins Giuliana has?


d – 22 + 0.25d = 10.75

0.25d + 22 – d = 10.75

0.25(22 – d) + d = 10.75

d + 0.25(d – 22) = 10.75

Answer 1

C.
`0.25(22-d)+d=10.75`

Explanation:

Let d represent the number of dollar coins.

We have been given that Giuliana has 22 quarters and dollar coins. So number of quarter coins would be
`22-d`.

We know that value of a quarter is $0.25. So all quarter coins will be worth
`0.25(22-d)`

We are also told that these coins worth a total of $10.75. This means that d dollar coins and
`0.25(22-d)` worth 10.75. We can represent this information in an equation as:

`0.25(22-d)+d=10.75`

Therefore, option C is the correct choice.

Upon solving our equation we will get,

`5.5-0.25d+d=10.75`

`5.5+0.75d=10.75`\

`5.5-5.5+0.75d=10.75-5.5`

`0.75d=5.25`

`(0.75d)/(0.75)=(5.25)/(0.75)`

`d=7`

Therefore, Guiliana had 7 dollar coins.