Answer:
a. 
b. 
Step-by-step explanation:
First, we need tot find a general expression for the amount of caffeine remaining in the body after certain time. As the problem states that every hour x percent of caffeine leaves the body, we must substract that percentage from the initial quantity of caffeine, by each hour passing. That expression would be:

Then, to find the amount of caffeine metabolized per hour, we need to differentiate the previous equation. Following the differentiation rules we get:

The rate is negative as it represents the amount of caffeine leaving the body at certain time.
7,3...
since we don't know how many stops after there are we will assume it just continues on and put three dots. (...)
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Answer:
I pretty sure I answered this for you like 10-15 minutes ago
Answer:
t = 8
Step-by-step explanation:
I think she will win a total of 4 prizes, because if she has 2.00 then divide by 10, then divide that by 5 I hope I have helped!