Answer: you choke and die by the time you hit 41 left :)
Answer: Tammy's sample may not be vaild because she surveyed the students only from her class and it is likely that other classes might not like the subject maths. She might get the accurate results by surveying a larger number of people in the school instead of just her class.
The axis of symmetry is given by the line x = a (where a is equivalent to the x-value of the turning point of the parabola) and can be viewed as the line about which the parabola is symmetric; in this case, the parabola has an axis of symmetry of x = 2, thus the answer is B