Question
A boat covers a total downstream distance of 180 km,
split into two equal parts. The boat’s speeds in these two parts are 2a km/h and 4a km/h respectively. The speed of the stream is a km/h. If the total time taken by the boat is 15 hours, find the value of ‘a’.Solution
ATQ,
Speed of the boat downstream = (2a + a) = 3a km/h and (4a + a) = 5a km/h respectively.
According to the question,
90/3a + 90/5a = 15
30/a + 18/a = 15
48/a = 15
a = 3.2
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