Probability of rolling a factor of 45

Olivia uses the work below to determine 55% of 720 which explains the error in olivia’s solution

Evaluate-27 ^4/3/8 a) - 81/16 b) 81/16 c) 16/81

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)