1. Class 10
  2. Solutions of Sample Papers for Class 10 Boards
  3. CBSE Class 10 Sample Paper for 2021 Boards - Maths Standard

Question 21 - CBSE Class 10 Sample Paper for 2021 Boards - Maths Standard

Last updated at Oct. 19, 2020 by

3 bells ring at an interval of 4, 7 and 14 minutes. All three bell rang at 6 am, when the three balls will the ring together next?

Slide58.JPG

Slide59.JPG
Slide60.JPG

  1. Class 10
  2. Solutions of Sample Papers for Class 10 Boards

    3. CBSE Class 10 Sample Paper for 2021 Boards - Maths Standard

    CBSE Class 10 Sample Paper for 2021 Boards - Maths Basic →

Transcript

Question 21 (Introduction) 3 bells ring at an interval of 4, 7 and 14 minutes. All three bell rang at 6 am, when the three balls will the ring together next? Let the bells ring at 1, 2, 3 minutes At 6 minutes, all of them ring together. Now, this 6 is actually the LCM of 1, 2, 3 So, Time when they ring together = LCM of 1, 2, 3 Question 21 3 bells ring at an interval of 4, 7 and 14 minutes. All three bell rang at 6 am, when the three balls will the ring together next? Here, Time when they next ring together = LCM of 4, 7 and 14 Finding LCM Thus, LCM = 2 × 2 × 7 = 28 Thus, the three bells ring together after 28 minutes Hence, Time when the three bells ring together is 6:28 am

Class 10
Solutions of Sample Papers for Class 10 Boards

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.