Multiple choice

The speed of the boat in still water is 12 kmph. It can travel downstream through 45 kms in 3 hrs. In what time would it cover the same distance upstream?

  1. 3 hours

  2. 4 hours

  3. 5 hours

  4. 7 hours

  5. 9 hours
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Downstream speed = 45 km / 3 hrs = 15 kmph. Speed of current = downstream speed - still water speed = 15 - 12 = 3 kmph. Upstream speed = still water speed - current = 12 - 3 = 9 kmph. Time upstream = 45 / 9 = 5 hours. Option A (3 hours) incorrectly assumes upstream equals downstream time. Option B (4 hours) is an arithmetic error. Options D (7 hours) and E (9 hours) don't match the calculated upstream speed.

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