The down stream speed of a boat is 100km/hr and its up stream speed is 50km/hr, then find the speed of stream? Choose the correct choice from the following answers:
A) 20km/hr B) 50km/hr C) 100km/hr D) 25km/hr E) 15km/hr
speed of stream = (100-50)/2= 
<gadget id="calculator">(100-50)/2</gadget>
<output>25</output>
25 km/hr   Answer is 25km/hr
<result>D</result>
The down stream speed of a boat is 100km/hr and its up stream speed is 50km/hr, then find the speed of stream?