Respuesta :
Answer:
The rate of boat in still water is 58 km/h
and, the rate of water is 11 km/h
Explanation:
Given:
While going upstream
distance = 188 km
Time = 4 hours
net speed of the motorboat = distance / time
thus,
the net upstream speed of the motorboat = ( 188 / 4) = 47 km/hr
now,
while moving in the downstream
distance = 276 km
Time = 4 hours
thus,
the net upstream speed of the motorboat = ( 276 / 4) = 69 km/hr
Let the rate of the water current be 'x' and the rate of motor boat in still water be 'y'
now, while moving upstream the rate of water will try to reduce the speed and while moving downstream the water current will add to the rate of the boat
thus,
for upstream the net rate = y - x = 47 km/h
and, for the downstream the net rate = y + x = 69 km/h
therefore on solving the above equations, we get
y - x = 47
- (y + x = 69 )
----------------------
0 - 2x = - 22
or
x = 11 km/h
substituting the value of x to find the y
we have
y - x = 47
or
y - 11 = 47
or
y = 58 km/h
hence,
the rate of boat in still water is 58 km/h and the rate of water is 11 km/h
Answer:
The rate of the boat in still water is 58 km/h.
The rate of the current in still boat is 11 km/h.
Explanation:
Given that,
Distance in upstream = 188 km
Distance in downstream = 276 km
Time = 4 hrs
We need to calculate the speed
Let x be the speed of boat in still water and y be the speed of current.
Speed of boat upstream= x-y
For upstream,
[tex]x-y=\dfrac{188}{4}[/tex]
[tex]x-y=47[/tex]
Speed of boat downstream= x+y
For downstream,
[tex]x+y=\dfrac{276}{4}[/tex]
[tex]x+y=69[/tex]
solve system of equation of x and y and we get
x=58 km/h and y=11 km/h
Hence, The rate of the boat in still water is 58 km/h.
The rate of the current in still boat is 11 km/h.
