Question

A boat can travel with a speed of 19 km/h in still water. If the speed of the stream is 5 km/h. Find the time taken by the boat to go 72 km downstream.
1. 3 hours
2. 5 hours
3. 8 hours
4. 4 hours

Answer 1

Correct Answer - Option 1 : 3 hours

GIVEN:

Speed of boat = 19 km/h

Speed of stream = 5 km/h

Distance = 72 km

FORMULA USED:

Time = Distance/Speed

Speed Downstream = Speed of boat + speed of stream

CALCULATION:
Let time taken be x hours 

Speed downstream = 19 + 5 = 24 km/h

Time = x = 72/24

x = 3 hours

∴ Time taken will be 3 hours.