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Pair of Linear Equations in Two Variables
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28/05/2021 10:59 am
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Ritu can row downstream 20 km in 2 hours, and upstream 4 km in 2 hours. Find her speed of rowing in still water and the speed of the current.
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28/05/2021 11:01 am
Let us consider,
Speed of Ritu in still water = x km/hr
Speed of Stream = y km/hr
Now, speed of Ritu during,
Downstream = x + y km/h
Upstream = x – y km/h
As per the question given,
2(x+y) = 20
Or x + y = 10 ……………………….(1)
And, 2(x-y) = 4
Or x – y = 2 ………………………(2)
Adding both the eq.1 and 2, we get,
2x = 12
x = 6
Putting the value of x in eq.1, we get,
y = 4
Therefore,
Speed of Ritu rowing in still water = 6 km/hr
Speed of Stream = 4 km/hr