math
posted by Anonymous .
A bell rings every 2 hours, a second bell rings every 3 hours, and a third bell rings every 4 hours. If all 3 bells ring at 9:00 AM. , at what time will all 3 bells next ring?

The LCM of 2, 3 and 4 is 12.
Therefore you must wait 12 hours, until 9:00 PM. 
THERE WALL CLOCK ARE THE ROOM ALL THE CLOCK RINGING TOGETHER AT 6 OCLOCK IN THE MORNING AFTER THAT1ST CLOCK RINGS ONCE FOR EVERY 20 MINUTES & 2ND CLOCK RINGS ONCE FOR EVERY 30 MINUTES & 3RD CLOCK RINGS FOR EVERY 40MINUTES WHAT WOULD BE THE TIME AT WHICH ALL THE CLOCK RING TOGETHER FOR THE SECOND TIME.
WHAT IS THE FORMULA...& WHAT IS THE ANSWER..