Let the distance covered in one direction be x km.
Then, speed upstream = x445 km/hr
( 8 hrs 48 min = 84860=845hrs)
= 5x44 km/hr
Speed downstream = x4 km/hr
∴ Speed of boat in still water = 12(5x44+x4)
= 8x44=2x11 km/hr
Speed of current = 12(x4−5x44)=3x44 km/hr
∴ Required ratio = 2x11:3x11=8:3