Answer : 1. "4 kmph"
Explanation :

Answer: A) 4 kmph Explanation: Let the speed of current = 'C' km/hr   Given the speed of boat in still water = 6 kmph   Let 'd' kms be the distance it covers.   According to the given data,   Boat takes thrice as much time in going the same distance against the current than going with the current   i.e, d8 - C = 3 × d8 + C   ⇒ 24 - 3C = 8 + C⇒ 4C = 16⇒ C = 4 kmph   Hence, the speed of the current C = 4 kmph.