Jcpenny wrote:

For a convention, a hotel charges a daily room rate of $120 for 1 person and x dollars for each additional person. What is the charge for each additional person?

(1) The daily cost per person for 4 people sharing the cost of a room equally is $45.

(2) The daily cost per person for 2 people sharing the cost of a room equally is $25 more than the corresponding cost for 4 people.

Slightly longer explanation:

Statement 1: If the average is $45, then the total cost per day is 4(45) = 180

With 4 people the cost is $120 + x + x + x

So, we get the equation 120 + 3x = 180 (clearly, we COULD solve this equation for x) --> sufficient

Statement 2:

The average cost for 2 people is (120+x)/2

The average cost for 4 people is (120+3x)/4

We know that the first average cost is $25 more than the second average, so we can create the equation (120+x)/2 = (120+3x)/4 + 25

(clearly, we COULD solve this equation for x) --> sufficient

Answer: D