πŸ“’ Too many exams? Don’t know which one suits you best? Book Your Free Expert πŸ‘‰ call Now!

  • google app store apple app store
  • βœ–

      Question

      A boat can travel 18 km more in downstream than that in

      upstream, in 9 hours while the difference between the time taken by the same boat to travel 200 km and 100 km, in still water, is 5 hours. Find the approximate time taken by the boat to travel 250 km in downstream and 200 km in upstream.
      A 12 hours Correct Answer Incorrect Answer
      B 32 hours Correct Answer Incorrect Answer
      C 42 hours Correct Answer Incorrect Answer
      D 22 hours Correct Answer Incorrect Answer
      E None of these Correct Answer Incorrect Answer

      Solution

      Let the speed of boat in still water and speed of stream be 'x' km/hr and 'y' km/hr, respectively. According to question; (200/x) - (100/x) = 5 Or, (100/x) = 5 So, x = 20 Now, 9 x (20 + y) = 9 x (20 - y) + 18 Or, 180 + 9y = 180 - 9y + 18 Or, 18y = 18 So, y = 1 So, downstream speed of the boat = (20 + 1) = 21 km/hr And, upstream speed of the boat = (20 - 1) = 19 km/hr Required time taken = (250/21) + (250/19) ~ (12 + 10) ~ 22 hours

      Practice Next

      Relevant for Exams:

      ask-question