Answer:
the answer is Theresa's speed was increasing for a longer period of time than it was decreasing.
Step-by-step explanation:
Theresa's speed was increasing from 0 to 5 minutes and from 20 to 25 minutes, which is a total of 10 minutes. Theresa's speed was decreasing from 10 to 20 minutes and from 20 to 30 minutes, which is a total of 15 minutes. Therefore, Theresa's speed was NOT increasing for a longer period of time than it was decreasing.