Question

In a fixed time, a boy swims thrice the distance along the current that he swims against the current. If the speed of the current is 11 km/hr, the speed of the boy in still water is

A 22 km/hr Correct Answer Incorrect Answer
B 20 km/hr Correct Answer Incorrect Answer
C 16 km/hr Correct Answer Incorrect Answer
D 24 km/hr Correct Answer Incorrect Answer
E 26 km/hr Correct Answer Incorrect Answer

Solution

Let the rate of swimming in still water be x km/hr Rate down-stream = (x + 11) km/hr Rate up-stream = (x – 11) km/hr According to the question, (x + 11) t = 3 (x – 11) × t x + 11 = 3x – 33 x = 22 km/hr

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