Question
 A man goes downstream with a boat to some destination
and returns upstream to his original place in 10hours. If the speed of the boat in still water and the stream are 10km/h and 4km/h respectively, the distance of the destination from the starting place is. Â type-sscSolution
Let the speed of boat in still water =B and speed of stream =S then Given – B=10km/h, S=4km/h Speed of boat in downstream =B+S=10+4=14 B+S=14          … (1) Speed of boat in upstream =B-S=10-4=6 B-S=6 … (2) Average speed = (14×6)/14+6 =84/20=4.2km/h now the distance of the destination from the starting place is. =10×4.2 =42km.
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