A son and father goes for boating in river upstream . After rowing for 1 mile son notices the hat of his father falling in the river. After 5 min. he tells his father that his hat has fallen. So they turn round and are able to pick the hat at the point from where they began boating after 5min. Tell the speed of river?

• Let speed of boat be V & strean be U
  In return downstream they travelled with speed of V+U for 5 min (1/12 hr)
  and covered a distance equal to that travelled in upstream with speed V-U for 5 min (1/12 hr) plus 1 mile travelled.
  so (V+U) *1/12 = (V-U) *1/12 +1
  Hence U =6 mph
• 10 years agoHelpfull: Yes(13) No(1)
• The hat fallen after travelling one mile and after that they
  travelled for (5MIN.)
  so that hat travelled down stream for one mile and they
  collected the hat after 5mins of travel down stream. So the
  total time they spent after losing hat is 10 minutes.In this
  10 minutes the hat exactly traveled 1 mile(i.e with river
  speed). So its very clear----> the river speed is 6miles/hour.
• 11 years agoHelpfull: Yes(8) No(2)
• can u explain plzzzz @ponnarasi
• 10 years agoHelpfull: Yes(3) No(0)
• Cap fell here
  
  A-------------->B----------------->C Upstream-------->
  1mile
  -----5 min--------
  
  A
• 12 years agoHelpfull: Yes(0) No(13)