The results of a bacterial blood infection of a lab rat are shown in the graph, where the vertical axis represents the number of bacteria per milliliter of blood and the horizontal axis represents time in hours since the rat was infected. If the rat is only considered "sick" with an infection rate of at least 30 bacteria per milliliter, for how long was this rat actually sick? 80- 60 40 20 10 15 20 O a 14 hours O b 6 hours 18 hours Od 22 hours

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question b

200 6. 10 Time (weeks) The graph above shows the accumulation of time, in hours, a student spent studying over a 10-week penod. The graph can be descnbed by the equation h= 1.9w, where h is the total hours spent thadymg and w is the number of weeks the student had been studying. What is the average rate of chamge, in hours per week, in the total time the student spent studying during the 10 weeks? hours per week Total Time Spent Studying 三 宫