There are 4 lunch choices in a school cafeteria: salad, pizza, spaghetti, and sub sandwiches. the percentage of students that chose salad is 15%. if 45 students chose salad, what is the total number of students that ate lunch?
a) 150
b) 200
c) 250
d) 300

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)