Three bikes, A, B and C, start racing at the same time and from the same point in the same direction in a circular path. A completes a round in 56 sec, B in 48 sec and C in 70 sec . After what time will they meet again at the starting point?

This question was previously asked in
CRPF Head Constable Ministerial Official Paper (Held On: 24 Feb 2023 Shift 2)
View all CRPF Head Constable Papers >
  1. 32 minutes
  2. 36 minutes
  3. 20 minutes
  4. 28 minutes

Answer (Detailed Solution Below)

Option 4 : 28 minutes
Free
CRPF Constable (Technical & Tradesmen) Full Mock Test
91.7 K Users
100 Questions 100 Marks 120 Mins

Detailed Solution

Download Solution PDF

Given:

Time taken by A to complete a round = 56 sec

Time taken by B to complete a round = 48 sec

Time taken by C to complete a round = 70 sec

Calculation:

Finding LCM of 56, 48, and 70:

Prime factorization of 56 = 23 × 7

Prime factorization of 48 = 24 × 3

Prime factorization of 70 = 2 × 5 × 7

LCM = 24 × 3 × 5 × 7

⇒ LCM = 16 × 3 × 5 × 7

⇒ LCM = 16 × 105

⇒ LCM = 1680 seconds

1680 seconds = 1680 / 60 minutes = 28 minutes

They will meet again at the starting point after 28 minutes.

Latest CRPF Head Constable Updates

Last updated on Jun 11, 2024

-> CRPF Head Constable 2024 Detailed Notification has been released!

-> A total of 282 vacancies have been announced for both Male and Female candidates.

-> Interested candidates can apply online from 9th June to 8th July 2024. 

-> The selection process includes a Computer-Based Test, Skill Test, Physical Standard Test (PST), Document Verification, and Detailed Medical Examination (DME).

-> Refer to CRPF Head Constable Previous Year Papers here!

More LCM and HCF Questions

Get Free Access Now
Hot Links: teen patti gold real cash teen patti fun teen patti king teen patti master king teen patti vip