Question

A boat can travel with a speed of 13 km/hr in still water. If the speed of the stream is 4 km/hr, find the time taken by the boat to go 68 km downstream.
1. 4 hrs
2. 5 hrs
3. 2 hrs
4. 3 hrs

Answer 1

Correct Answer - Option 1 : 4 hrs

Given:

Speed of the boat in still water = 13 km/h 

Speed of the stream = 4 km/h 

Formulas used:

Downstream (Speed) = Speed of the boat + Speed of the current 

Time = Distance/Speed 

Calculation:

Time = 68/(13 + 4) 

⇒ 68/17 = 4 hours 

∴ The required time = 4 hours