Question

Five bells ring together at the intervals of 3, 5, 8, 9 and 10 seconds. All the bells ring simultaneously at the same time. They will again ring simultaneously after:
1. 6 minutes
2. 4 minutes
3. 9 minutes
4. 8 minutes

Answer 1

Correct Answer - Option 1 : 6 minutes

Given:    

Five  bell rings together at the intervals of 3,5,8,9 and 10 second

 Calculation: 

By taking the LCM for 3, 5, 8, 9 and 10 seconds = 360 seconds 

⇒1 minute = 60 second 

So that,1 seconds= 1/60 min

⇒ 360 seconds = 360/60 = 6 minutes

∴ All the bell rings together in 6 minutes.