A boat can move 7.5 kmph in still water .the speed of the stream is 1.5 kmph the boat takes 60 minutes to go from point A to B and return to the same point (A)what is the distance between the two points ?
Answers
Answer:
Step-by-step explanation:
Suppose the speed of boat in still water is x = 7.5kmph;
speed of stream y = 1.5kmph;
Speed downstream = x+y = 7.5+1.5 = 9 kmph;
Speed upstream = x-y = 7.5-1.5 = 6 kmph;
Boat is go from A to B and return to the same point means a boat is going in to upstream as well down stream while returning.;
total time = distance/ velocity;
Let distance = d;
60 min. = 1hr = (d/2)/9 + (d/2)/6;
1 = d/18 + d/12;
36 = 5d;
d = 7.2 km;
Distance between Point a to b = 7.2/2 = 3.6 km
Answer:
3.6 km
Step-by-step explanation:
A boat can move 7.5 kmph in still water .the speed of the stream is 1.5 kmph the boat takes 60 minutes to go from point A to B and return to the same point (A)what is the distance between the two points ?
Speed in still water = 7.5 kmph
Speed of stream = 1.5 kmph
Upstream speed = 7.5 - 1.5 = 6 km/hr
Downstream speed = 7.5 + 1.5 = 9 km/Hr
Let say distance from A to B = D km
Then time upstream = D/6 hr
Time Downstream = D/9 hr
D/6 + D/9 = 1 ( 60 mins = 1 Hr)
Multiplying by 18 both sides
=> 3D + 2D = 18
=> 5D = 18
=> D = 3.6 km