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

      Question

      The speeds of boats A and B in still water are in the

      ratio 5:3. The upstream speed of A is the same as the downstream speed of B. If the stream flows at 4 m/s, find the average of their downstream speeds.
      A 42 m/s Correct Answer Incorrect Answer
      B 32 m/s Correct Answer Incorrect Answer
      C 20 m/s Correct Answer Incorrect Answer
      D 18 m/s Correct Answer Incorrect Answer
      E None of these Correct Answer Incorrect Answer

      Solution

      Let the speed of boat A in still water be 5x m/s. So, the speed of boat B in still water = 3x m/s. ATQ, 5x − 4 = 3x + 4 ⇒ 2x = 8 ⇒ x = 4 Downstream speed of boat A = 5x + 4 = 5 × 4 + 4 = 24 m/s Downstream speed of boat B = 3x + 4 = 3 × 4 + 4 = 16 m/s Required average = (24 + 16) / 2 = 20 m/s

      Practice Next
      More Simple and compound interest Questions
      ask-question