Answer
$a). 96.4 km/hr$
b). She need NOT exceed the 65-mi/hr speed limit.
Work Step by Step
a). From 8.00 am to 3.00 pm, time difference is 7 hours.
So, average speed = $\frac{675km}{7hr}=96.4km/hr$
b). 1 mile = 1.609 km
65 mile/hr = $1.609 \times 65$ km/hr=104.6 km/hr.
Therefore, she need NOT exceed the 65-mi/hr speed limit.
