ANSWER
D. 5
EXPLANATION
In Company A, the charge is $125 annual fee plus $7 per hour car share fee.
In Company B, the charge is $110 annual fee plus $10 per hour car share fee.
Let x be the number of hours of a car share.
For Company A, we have that, the total charge is given as:
Charges = 125 + 7*x
C = 125 + 7x
For Company B, we have that, the total charge is given as:
Charges = 110 + 10 * x
C = 110 + 10x
To find the minimum number of hours that a car share in Company B needs to be used to make company a deal, we have to equate the charges for Company A and B so as to find x.
So, we have that:
125 + 7x = 110 + 10x
Collect like terms:
10x - 7x = 125 - 110
3x = 15
x = 15 / 3
x = 5 hours
So, the minimum number of hours that a car share in Company B needs to be used per year to make company A a deal is 5 hours (Option D)
