Correct option is (d) 10 am
The distance from A to B = 110km.
The biker from A starts at 7am.
So by 8 am he travels for 1 hr.
His speed = 20km/hr.
Then the distance covered form 7am to 8am = 20km.
Rest of the distance = (110 − 20)km = 90km.
Now the biker from B starts.
Their relative speed = (20 + 25)km/hr. = 45km/hr.
(since they are approaching each other.)
So, the time taken = \(\frac{\text{distance}}{\text{relative speed}}\)
\(= \frac{90}{45} \) hrs.
= 2 hrs.
So, they will meet each other after 3 hrs from 7am i.e at 10am.