Shankar can row upstream 5 km/h and downstream 10 km/h, the rate at which he rows in still water is :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 7.5 km/h
$x$ → Speed of row
$y$ → Speed of current
Downstream = $x+y=10\,km/hr$ ...(1)
Upstream = $x-y=5\,km/hr$ ...(2)
Add (1) and (2)
$2x=15$
$x=7.5\,km/hr$