SAT Math Multiple Choice Practice Question 109: Answer and Explanation
The graph above shows the weight of a hamster, in grams, over a period of several days. The linear function that best models the hamster's weight, w, as a function of its age in days, a, is which of the following?
A. w = 6a
B. w = 10a
C. w = 6a + 10
D. w = 10a + 6
E. w = 8a + 8
Correct Answer: C
C. The hamster seems to grow between 4 and 8 grams per day, which means that 6 is a reasonable slope for the function. Because it weighed 15 grams after 1 day, it's also reasonable for it to have weighed 10 grams or so at 0 days (although I have to admit that's a pretty big hamster).