Help i dont uderstand please help :(

Acourgette seed and a pumpkin seed is planted p(courgette seed germinates) 4/5 and p(pumpkin seed germinates) = 1/6 what is the probability that both seds germinate

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 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)