New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    Four lights blink at intervals of 18 seconds, 24

    seconds, 36 seconds, and 48 seconds respectively. How many times will all the lights blink together in 3 hours?
    A 90 Correct Answer Incorrect Answer
    B 75 Correct Answer Incorrect Answer
    C 65 Correct Answer Incorrect Answer
    D 45 Correct Answer Incorrect Answer

    Solution

    ATQ,

    All the lights will blink together after 144 seconds (LCM of 18, 24, 36 and 48)

    3 hours = 180 minutes

    Therefore, required number of times ≤ (180 × 60) ÷ 144 = 75

    Practice Next

    Relevant for Exams: