📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!

    Question

    Two classmates R and S stand at points U and V

    respectively. R starts toward V from U at a speed of (x – 5) km/h. After 3 hours, S starts toward U from V at a speed of (x + 5) km/h. They meet exactly at the midpoint of UV. If UV = 360 km, find the time taken by R to go from U to V.
    A 18 hrs Correct Answer Incorrect Answer
    B 20 hrs Correct Answer Incorrect Answer
    C 12 hrs Correct Answer Incorrect Answer
    D 10 hrs Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ, Distance covered by R in 3 hours = (x – 5) × 3 = 3(x – 5) km Remaining distance between them = 360 – 3(x – 5) = 360 – 3x + 15 = (375 – 3x) km Time of meet after S starts = (375 – 3x)/(2x) hours According to question, [(375 – 3x)/(2x)] × (x + 5) = 360/2 (375x + 1875 – 3x² – 15x) = 360x ⇒ –3x² + 1875 = 0 3x² = 1875 x² = 625 x = 25 Speed of R = 25 – 5 = 20 km/h Therefore, required time = 360/20 = 18 hours

    Practice Next
    More Time and distance Questions
    ask-question