4 bells toll together at 9.00 a.m. They toll after 7, 8, 11 and 12 seconds respectively. How many times will they toll together again in the next 3 hours ?

Five bells begin to toll together and toll respectively at intervals of 6, 5, 7, 10 and 12 seconds. How many times will they toll together in one hour excluding the one at the start?

Five bells begins to toll together and toll respectively at intervals 6,7,8,9 and 12 seconds. How many times will they toll together in one hour, excluding the one at the start?

Five bells begins to toll together and toll respectively at intervals 6,7,8,9 and 12 seconds. How many times will they toll together in one hour, excluding the one at the start?

Five bells begin to toll together at intervals of 9s,6s,4s,10s and 8s,respectively. How many times will they toll together in the span of 1 h (excluding the toll at the start)?

Three bells rang together at 8.30 a.m. If they rang at intervals of 4, 5 and 6 minutes respectively, when will they ring together again?