To rent a room for a party at an ice-skating rink, the charge is $50 per hour plus $2 per person attending the party. Which of the following functions represents the charge, in dollars, to rent a room at the rink for a 2-hour party if n people attend the party?
A. f(n) = 102n
B. f(n) = 200n
C. f(n) = 100n + 2
D. f(n) = 100 + 2n
E. f(n) = 100 + 2n
Explanation: If the charge to rent a room is $50/hour, and you are trying to rent a room for 2 hours, you know the cost of just renting the room is:
$50/hour x 2 hours = $100
Any additional cost for renting the room is associated with the number of people who attend the party. The charge is $2 per person, or:
Added together, these two values are the total amount to rent a room at the ice-skating rink for a party. The total amount of money it would cost, represented as an equation, looks like:
$100 + $2n
Because we are being asked to express this as a function in dollars, we must express it as such:
f(n) = 100 + 2n
The answer is therefore (D).