Correct Answer - Option 4 : 27.5 min
Speed of P = 11km/h
Speed of Q = 13 km/h
Starting time of P = 8 am
Starting time of Q = 9 am
Speed = Distance/Time
If two objects are moving with speeds S1 and S2 in the opposite direction
Their relative speed is S1 + S2
Distance traveled by P in 1 hour = 11 × 1 = 11 km
Distance traveled by P till 9 am = 11km
11 km is to be covered with the relative speed of both to meet.
Relative speed = 11 + 13 =24 km
Time required = 11/24 h = 11/24 × 60 min = 27.5 min
∴ They will meet after 27.5 minutes.