Question

Three bells ring at intervals of 18 seconds, 24 seconds, and 30 seconds. If they all start ringing together at 10:00:00 AM, after how many minutes will they ring together again?

Asked in SSC GD Constable · 2026
LCM and HCF · Quantitative Aptitude
Exam PYQ4 Options
Quantitative AptitudeNumber SystemLCM and HCFLCMInteger BasedSSC GD Constable2026
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If one number is already a multiple of all the other given numbers, that largest number itself is their LCM.

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Questions Asked from LCM: Prime Factorisation & The Ladder Method in Previous Exams

See how often LCM: Prime Factorisation & The Ladder Method has appeared in previous-year questions across major government exams.

High Exam Frequency
15UPSC Questions Asked in These Years:2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2022, 2023, 2024, 2026
9SSC Questions Asked in These Years:2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026
7Railways Questions Asked in These Years:2016, 2018, 2021, 2022, 2024, 2025, 2026
16State PSC Questions Asked in These Years:2002, 2004, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025
LCM: Prime Factorisation & The Ladder Method has appeared in 47 previous-year exam questions, most frequently in State PSC, UPSC and SSC.
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