Shortcuts to solve Problems on Boats and Sreams
Problems on Boats and Streams are quite common as questions from this topic come every year in various competitive exams like Banking, SSC, CSAT, etc. The basic concepts of Time, Speed and Distance are used in solving Problems on Boats and Streams. So, let us first go through some basic concepts of Boats and Streams.
If the speed of boat in still water is kmph and the speed of the stream is kmph then, the speed at which boat will travel with the stream or,
If the speed of boat in still water is kmph and the speed of the stream is kmph then, the speed at which boat will travel against the stream or,
Example: A man can row 8 kmph in still water and the river is running at 2 kmph. If the man takes 1 hour to row to a place and back, how far is the place?
SPEED OF BOAT IN STILL WATER AND SPEED OF STREAM
If the downstream speed is kmph and upstream speed is kmph then,
Example: A man can row upstream at 7 kmph and downstream at 10 kmph. Find man’s rate in still water and the rate of current.
SOME SHORTCUT METHODS
• If a person rows certain distance downstream in t1 hours; returns the same distance upstream in t2 hours; and the speed of stream is y kmph, then the speed of man in still water is given by:
• If a person rows in still water at x kmph in a stream flowing at y kmph and if it takes him t hours to row to a place and come back, then the distance between two places is given by:
• If a person rows in still water at x kmph in a stream flowing at y kmph, if it takes t hours more in upstream than to go downstream for the same distance, then the distance is given by:
• A person can row in still water at x kmph. In a stream flowing at y kmph, if he rows the same distance up and down the stream, then his average speed is given by: