Multiple choice

Vihang rowed upstream $48$kms. and back in $14$ hourse. He can row $4$kms. downstream in the same time as $3$kms. Find the flow of the stream

  1. $1$km/hr.
  2. $0.5$km/hr.
  3. $0.75$km/hr.
  4. $1.5$km/hr.
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A Correct answer
Explanation

Let the downstream and upstream speeds be d and u. Since 4 km downstream takes the same time as 3 km upstream, d/u = 4/3. Combining this with 48/u + 48/d = 14 gives d = 8 and u = 6, so the stream speed is (8 - 6)/2 = 1 km/hr.

AI explanation

Let the time taken to row downstream 4 km and upstream 3 km be t hours, making the downstream speed 4/t and upstream speed 3/t. Using the formula speed equals distance over time, 48 divided by (4/t) plus 48 divided by (3/t) equals 14, which simplifies to 12t + 16t = 14, so t equals 1/2. This gives a downstream speed of 8 km/hr and upstream speed of 6 km/hr, and the speed of the stream is half their difference, (8 - 6) / 2, which equals 1 km/hr.

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