Question

Peppy Pets charges a flat fee of $15 plus $3 per hour to keep a dog during the day. Happy Hounds charges a flat fee of $21 plus $1 per hour. For how many hours is the total fee charged by the companies the same? a) 4 hours b) 5 hours c) 2 hours d) 3 hours

Answer 1

Answer: d) 3 hours.

Explanation:

Let x be the required number of hours for which the total fee charged by the companies the same.

Given: Peppy Pets charges a flat fee of $15 plus $3 per hour .

So Total charge = 15+3x ( in dollars)

Happy Hounds charges a flat fee of $21 plus $1 per hour.

So Total charge = 21+x ( in dollars)

When the total charge for both companies are the same, then

`15+3x=21+x\\\\\Rightarrow\ 3x-x=21-15\\\\\Rightarrow\ 2x=6\\\\\Rightarrow\ x=3`

Hence, the correct option is d) 3 hours.