Question

$3$ bells ring at an interval of $4$, $7$ and $14$ $minutes$. All three bell rang at $6am$, when the three balls will the ring together next?

Answer 1

Given that, $3$ bells ring at an interval of $4$, $7$ and $14$ $minutes$.

To find the time interval at which they rang again we have to find L.C.M of three time intervals.
Let us find the L.C.M of $4$, $7$ and $14$.
$$\begin{gathered} 4=2\times 2 \\ 7=7\times 1 \\ 14=2\times 7 \end{gathered}$$
$LCM(4,7,14)=2\times 2\times 7=28$
Therefore, all the three balls will ring together again at $6:28am$.