Answers

2015-02-11T17:44:22+05:30
Down stream speed= distance/time= 12 km, 0.8 hr
                                     =120/8=15 km/hr
sailor's speed=x
river's speed=y
x+y=15
x=15-y
upstream speed=12/1.2=120/12=10 km/hr
x-y=10
15-y-y=10
15-2y=10
2y=5
y=2.5 km/hr
sailor's speed=15-2.5=12.5 km/hr
0