If repetition of digits is allowed, how many different ways 5-digit codes are possible with the condition that the first digit should be a multiple of 3 and the last digit cannot be zero. a. 17496.
b. 27000.
c. 18000.
d. 30000.

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)