A rumor about canceling spring break is being spread around a school.

A rumor about canceling spring break is being spread around a school. The following equation models the number of students in the school who have heard the rumor after t days:
N(t)=18001+149e−0.625t
A.). How many people started the rumor?
B. ). How many students are in the school?
C.). To the nearest 1/10, how many days will it be before the rumor spreads to ½ the student body?
D.). The following equation represents the instantaneous rate of change in students per day of the spread of the rumor.
N1(t)=0.625N(1−N1800)
N represents the number of students who have heard the rumor and t is time in days.
How many students have heard the rumor when the rumor is spreading the fastest?
What is the rate of change in students per day at this time ?