a sailor goes 24km downstream 48km upstream in 8hours while he goes 48km in downstream and 24km upstream in 7 hours. find speed of boat and stream
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sorry for keeping you waiting.
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BrainMaster11:
k.. i am waiting.
thanks for the equations..but can u please provide the full solved equation
Answered by
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Let the speed of sailor = x
speed of boat = y
24/x+y + 48/x-y = 8
3/x+y + 6/x-y = 1
1/x+y + 2/x-y= 1/3
2/x+y + 4/x-y = 2/3(16/24).............(1)
Second Case
48/x+y + 24/x-y = 7
2/x+y + 1/x-y = 7/24................(2)
8/x+y + 4/x-y = 28/24..................(3)
(1) - (2) = 3/x-y = 9/24
= x-y = 8 ...........(4)
(3) - (1) = 4/x+y =1/3
x+y = 12...(5)
Solving (4) and (5)
x+y+x-y=2x= 20
x= 10
y=2
speed of boat = y
24/x+y + 48/x-y = 8
3/x+y + 6/x-y = 1
1/x+y + 2/x-y= 1/3
2/x+y + 4/x-y = 2/3(16/24).............(1)
Second Case
48/x+y + 24/x-y = 7
2/x+y + 1/x-y = 7/24................(2)
8/x+y + 4/x-y = 28/24..................(3)
(1) - (2) = 3/x-y = 9/24
= x-y = 8 ...........(4)
(3) - (1) = 4/x+y =1/3
x+y = 12...(5)
Solving (4) and (5)
x+y+x-y=2x= 20
x= 10
y=2
why did u write 16/24 in eq 1?
btw thanks
Welcome :)
I made it 16/24 to make it easier to subtract it from 7/24..(2)
and why did u make eq 3??
To get the value of (x+y) in eqn(5)
In eqn (2) and eqn(1), 2/x+y was common in both so they will cancel out to give x-y value
and in eqn(3) and (1) 4/x-y is common so they will cancel out to give the value of x+y
and in eqn(3) and (1) 4/x-y is common so they will cancel out to give the value of x+y
To get the value of x+y we have to cancel out the part with x-y as denominator and vice versa..let me know if you have any doubts
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