Answer:
2 and 2/3 mph
Explanation:
The computation of the speed when he wants to keep the same distance is shown below:
Given that
Jenny left her house at 8:00AM
Went for a school at a speed of 2 and 2/3 mph
And, her brother left the house minutes later
So here the speed would be the same i.e. 2 and 2/3 mph