Ms. Kincaid keeps a supply of dimes and quarters in her car to pay for highway tolls. A week's supply of toll coins contains 5 more dimes than quarters and totals $4.00. How many quarters does Ms. Kincaid spend on highway tolls in one week

A. 10

B. 15

C. 16

D. 40

Answer: (A) 10

Step-by-step explanation:

Value Quantity = TOTAL Value

dimes:.10 Q + 5 =.10 (Q = 5)

quarters:.25 Q =.25Q

Dimes + Quarters = $4.00

.10 (Q + 5) +.25Q = 4.00

.10Q +.50 +.25Q = 4.00

.50 +.35Q = 4.00

.35Q = 3.50

Q = 10

Quarters = 10

Dimes = Q + 5

= 10 + 5

= 15

Answer: Option A, she has 10 quarters.

Step-by-step explanation:

We have quarters of $0.25 and dimes of $0.10

We have 5 more dimes than quarters and a total of $4.00

How many quarters Ms. Kincaid has?

Q is the number of quarters and D the number of dimes.

We have the system of equations:

D = Q + 5

Q*$0.25 + D*$0.10 = $4.00

First, we can replace the first equation into the second and solve it for Q.

Q*$0.25 + (5 + Q) * $0.10 = $4.00

Q * ($0.25 + $0.10) + $0.50 = Q * ($0.35) + $0.50 = $4.00

Q = (4.00 - 0.50) / 0.35 = 3.50/0.35 = 10

So she has 10 quarters.

The correct option is A.