A boat whose speed is 15 k/hr in still water goes 30 k/he downwards and come back in total 4 hr 30 min what is the speed of stream in k/hr ?  Answers: A) 1km/hr B) 2km/hr C) 3km/hr D) 4km/hr E) 5km/hr
If the speed of stream=x   Speed in downstream=15+x , Speed in Upstream=15-x,   Total time=4 hr 30 min=9/2 hr   [30/(15+x) + 30/(15-x)]=9/2,Solving x=5   x=5km/hr   ANSW5km/hrR:5km/hr
<result>E</result>
A boat whose speed is 15 k/hr in still water goes 30 k/he downwards and come back in total 4 hr 30 min what is the speed of stream in k/hr ?