arithmetic - peter can row 40 km upstream and 55 km downstream in 13 hours also he can row 30 km upstream and 44 km downstream in 10 hoursfind the speed of the peter in still water and the speed of the current - skillgun

Let rate upstream = x km/hr
and rate downstream = y km/hr.
Then,40/x +55/y = 13...(i)
and 30/x +44/y = 10
Multiplying (ii) by 4 and (i) by 3 and subtracting ,we get:11/y = 1 or y = 11.
Substituting y = 11 in (i),
we get: x = 5.
Rate in still water =1/2(11+5) kmph = 8 kmph.
Rate of current=1/2(11-5)kmph = 3 kmph