2. Sample Papers
  3. Railways
  4. Quantitative Aptitude
  5. LCM & HCF

Railways Quantitative Aptitude LCM & HCF Sample Paper HCF and LCM Sample Test Paper-2

  • question_answer
    Four bells begin to toll together and toll respectively at intervals of 6, 5, 7, 10 and 12 seconds. How many times they will toll together in one hour excluding the one at the start?

    A)  7 times

    B)  8 times

    C)  9 times

    D)  11 times

    Correct Answer: B

    Solution :

    [b] LCM of 6, 5, 7, 10 and 12 = 420 seconds \[=\frac{420}{60}=7\,\operatorname{minutes}.\] Therefore, in one hour (60 minutes), then will fall together 8 times \[\left( \frac{60}{7} \right)\] excluding the one at the start.


You need to login to perform this action.
You will be redirected in 3 sec spinner