Question
The ratio of the speed of a boat in downstream and speed
of the stream is 7:2. If the speed of the current is 4 km/hr, then find the distance travelled (in km) upstream in 3 hours.Solution
Let speed of downstream and speed of stream be 7x and 2x respectively. Speed of current => 2x = 4 => x = 2 km/hr Downstream speed = 7 * 2 = 14 km/h Speed of boat = 14 - 4 = 10 km/hr Upstream speed = 10 - 4 = 6 km/h Distance travelled upstream in 3 hr = 6 * 3 = 18 km.
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