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:

6 minutes 8 minutes 9 minutes 4 minutes

6 minutes

The LCM for 3, 5, 8, 9 and 10 seconds = 360 seconds  ⇒1 minute = 60 second  So that,1 seconds= \(\frac{1}{60}\)  min ⇒ 360 seconds = \(\frac{360}{60}\)  = 6 minutes