A boat travels 24 km upstream in 6 h and 20 km downstream in 4 h then the speed of a boat in still w...........

Quantitative Aptitude (SBI-CL) Boats and Streams

A boat travels 24 km upstream in 6 h and 20 km downstream in 4 h. then, the speed of a boat in still water and the speed of current are respectively.

4.5 km/h and 3 km/h

4.5 km/h and 0.5 km/h

4 km/h and 2 km/h 5 km/h and 2 km/h

5 km/h and 2 km/h

None of these

Distance travelled by boat in upstream=24km

Time taken = 6 h

Speed of the boat in upstream = 24/6 = 4 km/h

And distance travelled by boat in downstream = 20 km

Time taken = 4h

Speed of the boat in downstream = 20/4 km/h = 5 km/h

Now, speed of the boat in still water = 1/2 [ speed of the boat in upstream + speed of the boat in downstream] =1/2 [4 + 5] = 1/2 × 9 = 4.5 km/h

And speed of the current = ½ [speed of the boat in downstream – speed of the boat in upstream] = 1/2 [5 – 4] = 1/2 × 1 = 0.5 km/h

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