Question
A school drum beats every 12 minutes, and the school bell rings every 18 minutes. If both sounded together at 9:00 AM, how many times will they sound together again before 11:00 AM?
Asked in RRB NTPC (UG) CBT-I · 2026
LCM and HCF · Quantitative Aptitude
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Before using ratio-based LCM shortcuts, simplify the ratio first so that the ratio terms are co-prime.
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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.
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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