Q. The distance between Y to Z is ‘m’ km. And the distance between X to Y is ‘m+56’ km. Boat A travels downstream from point X to Y and Boat B travels upstream from Y to Z. The speed of boat A in still water is 20℅ of ‘m’ and its equal to the upstream speed of boat B. Boat A travels downstream and it takes 20 minutes more time than the Boat B travels in Upstream. What is the distance between Y and Z, if the speed of the current is the same in both cases that is 8 km/hr?
A. 150 km
B. 224 km
C. 200 km
D. 194 km
E. None of these
Sol:
The speed of boat A in still water = 20/100 of m
=> 0.2 m km/hr
Speed of the current = 8 km/hr
Downstream speed of boat A = (0.2m + 8) km/hr
Boat A in still water = upstream speed of boat B
=> 0.2m
So, upstream speed of boat B = 0.2m km/hr
m+56/0.2m+8 – m/0.2m = 1/3
m+56/0.2m+8 = 16/3
3m + 168 = 3.2m + 128
0.2m = 40
m = 200
So, Distance between Y and Z = 200 km
