Answer:
Mr Burkett travelled 407.5 miles during his full trip.
Step-by-step explanation:
First, we must determine the distance he travelled in the first 3.5 hours. Luckily, we know his speed during that time so we can just multiply 70 miles per hour by 3.5 hours. That is 245 miles.
In the second step, we must determine the distance he travelled during the second part of his trip where he slowed down a bit. 65 miles per hour times 2.5 hours is 162.5 miles.
Finally, we can just add them! 245 + 162.5 = 407.5.