Answer:
28 km/h .
Explanation:
Let the initial speed of the biker be x km/h Increased speed of the bike will be (x+2)km/h
Time taken to cover half the distance
=2 h 30 min
=150 min
Time taken to cover the second half of the distance
=2 h 20 min
=140 min
We know that,
Distance= Speed × Time
We have,
Therefore, the initial speed of the biker is
28 km/h .