Question
Three machines in a factory make a beep sound after finishing their cycle times. Machine A beeps every 18 seconds, Machine B beeps every 30 seconds, and Machine C beeps every 45 seconds. If they all beep together at 8:00:00 a.m., what will be the next time they all beep together ?
Asked in UP Police SI (दरोगा) · 2026
LCM and HCF · Quantitative Aptitude
Exam PYQ4 Options
Quick Revision
If one number is already a multiple of all the other given numbers, that largest number itself is their LCM.
Correct AnswerCorrect option for this question
Learn LCM and HCF in 60 Seconds
Master two simple LCM methods and learn how to use Prime Factorisation and the Ladder Method without getting confused.
Everything you need to learn, practice & excel — in one place.
Video-Based Study Material
PYQ-Based Quizzes
1,000+ Informative Audiobooks
300+ Full-Length Mock Tests
Daily Current Affairs
5,000+ PYQs
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.
2-Minute Revision Notes
Revise LCM and HCF and Its Related Concepts
Strengthen key concepts with exam-focused visual notes for faster revision.
Explore More Questions
Continue practising by chapter, topic and related subjects.
One question solved. Keep going.
Continue with the next Number System question and build your accuracy one question at a time.