Correct Answer - Option 3 : 4
Given
Total speed of boat in upstream and downstream = 44 km/h
Formula used
Speed of the boat = [(speed of the boat in upstream) + (speed of the boat in downstream)]/2
Calculation
Speed of the boat = 44/2 km/hour = 22km/hour
The speed of the boat in upstream = 22 - 4 = 18 km/hour
Time taken to travel 56 km = 72/18 = 4 hours
∴ Time taken by Raman to travel 72 km is 4 hours.