In a certain biology experiment, the number N of bacteria increases with time t in hours...

In a certain biology experiment, the number N of bacteria increases with time t in hours as indicated in the following figure.

(a) How many bacteria are initially present when t = 0?

(b) Approximately how long does it take for the original colony to double in size?

(c) For which value of t is the population approximately 2500?

(d) During which time interval does the population increase more rapidly, between t = 0 and t = 1 or between t = 3 and t = 4?