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
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