A teacher divided the class into two groups of equal size. 3 5 of the first group are right-handed.

80% of the second group are right-handed.

What fraction of the class is right-handed?

A.4/5

B.7/10

C.5/7

D.8/9

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)