If a boat can row upstream at 12 km/hr, and downstream at 20 km/hr, then the speed (in km/hr) of the stream and the speed (in km/hr) of the boat in still water are respectively :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 4, 16
Speed of boat in still water = x km/hr
Speed of stream = y km/hr
Upstream speed = $x-y=12km/hr$ ....(1)
Downstream speed = $x+y=20km/hr$ ....(2)
from (1) and (2)
$(x+y)+(x-y)=32$
$2x=32$
$x=16km/hr,y=4km/hr$