📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!
  • google app store apple app store
    • âś–

      Question

      A boat covers a total distance of 48 km downstream and

      48 km upstream in 5 hours. Given that the speed of the stream is 4 km/h, what is the distance the boat covers upstream in 150 minutes?
      A 40 km Correct Answer Incorrect Answer
      B 32 km Correct Answer Incorrect Answer
      C 24 km Correct Answer Incorrect Answer
      D 60 km Correct Answer Incorrect Answer
      E None of these Correct Answer Incorrect Answer

      Solution

      Let the speed of boat in still water be 'v' km/h. ATQ, 48/(v + 4) + 48/(v - 4) = 5 Or, 48 X (v - 4 + v + 4) = 5 X (v2 - 16) Or, 48 X 2v = 5v2 - 80 Or, 5v2 - 96v - 80 = 0 Or, 5v2 - 100v + 4v - 80 = 0 Or, 5v(v - 20) + 4(v - 20) = 0 Or, (5v + 4) (v - 20) = 0 So, 'v' = 20 or 'v' = - (4/5) But speed cannot be negative. So, 'v' = 20 Upstream speed of boat = 20 - 4 = 16 km/h Therefore, upstream distance cover by boat in 150 minutes = 16 X (150/60) = 40 km

      Practice Next
      More Boats and streams Questions

      Relevant for Exams:

      ask-question