Theresa ran at a constant speed for minutes.
Theresa's speed was increasing for a longer period of time than it was decreasing.
Theresa's speed decreased at a constant rate during the last minutes.
Theresa's speed reached its maximum during the last minutes.
Explanation
Correct answer: B.
Choice B is correct. Theresa's speed was increasing from to minutes and from to minutes, which is a total of minutes. Theresa's speed was decreasing from minutes to minutes and from to minutes, which is a total of minutes. Therefore, Theresa's speed was NOT increasing for a longer period of time than it was decreasing.
Desmos solution:
Note: Read the graph to check each statement: increasing intervals are 0-5 and 20-25 (10 min), decreasing are 10-20 and 25-30 (15 min).
Enter in Desmos:
Reviewed and rewritten by CookSAT
Why the other choices are wrong
Choice A
Choice A is incorrect. Theresa ran at a constant speed for the -minute period from to minutes.
Choice C
Choice C is incorrect. Theresa's speed decreased at a constant rate during the last minutes, which can be seen since the graph is linear during that time.
Choice D
Choice D is incorrect. Theresa's speed reached its maximum at minutes, which is within the last minutes.