Answer- B
Basic Formula:
If the speed downloadstream is a km/ hr and the speed upstream is b
km/ hr
then Speed in still water is = ½ (a+b) km / hr [memory tool last 2 L
cross and make +] Explanation:
Given : speed downstream a = 6 km ph
Speed upstream b = 2kmph
Speed in still water = ½ (a+b) kmph
= ½ (6+2)
= 8/2 = 4kmph
speed in still water = 4kmph