Five bells first begin to toll together and then at intervals of 5, 10, 15, 20 and 25 seconds respectively. After what interval of time will they toll again together?  Choose the correct option.
A) 5 min B) 5.5 min C) 5.2 min D) 6.2 min E) None
LCM = 300/60= 
<gadget id="calculator">300/60</gadget>
<output>5</output>
5 min   5 minNSWER:5 min
<result>A</result>
Five bells first begin to toll together and then at intervals of 5, 10, 15, 20 and 25 seconds respectively. After what interval of time will they toll again together?