On the way to her babysitting job, mary rode her bike for the first mile. she stopped at a traffic light and waited a few minutes for the traffic light to turn green. she then walked her bike across the street and up a short steep hill. finally, she rode the bike at a constant speed for one more mile. if mary created a graph of her time and distance, which statement describes the part of her graph that would show no change in distance? mary used her bike to ride the first mile. mary stopped and waited for the traffic light to turn green. mary walked her bike across the avenue and up a short hill. mary rode her bike at a constant speed for one mile.

The biologist has a second culture to examine. she knows that the population of the culture doubles every 15 minutes. after 1 hour and 15 minutes, her assistant found that 80,000 bacteria were present. a) what was the size of the initial population? b) predict the size of the culture at t=3 hours. what was the size of the population at 40 minutes? explain and justify your answers. c) create a graph of the population as a function of time. find an equation that can be used to predict the size of the population at any time t. d) examine the rate at which the bacteria culture is growing. how fast is the culture growing after 1 hour? after 1.5 hours? after 2 hours? use a time interval of h = 0.01 hours to estimate these rates. interpret these rates in terms of the context of the problem situation. how do these three rates compare?