A boat can row upstream at 10 km/h and downstream at 18 km/h. If m is the speed of boat in still water and n is the speed of stream then $m+n $ is :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 18 km/h
m = Speed of the Boat
n = Speed of the Stream
∴ Speed of Boat, rowing downstream,
$m-n=10$ ....(1)
Speed of Boat, rowing upstream,
$m+n=18$ ....(2)
Add equation (1) and (2), we get
$2m=28$
$m=14⇒n=4$
$∴m+n=18$