An efficiency study conducted for elektra electronics showed that the number of space commander walkie-talkies assembled by the average worker during the morning shift t hr after starting work at 8 a. m. is given by n(t) = −t3 + 6t2 + 15t (0 ≤ t ≤ 4).
a. find the rate at which the average worker will be assembling walkie-talkies t hr after starting work.
b. at what rate will the average worker be assembling walkie-talkies at 10 a. m.?
c. how many walkie-talkies will the average worker assemble between 10 a. m. and 11 a. m.?