Answer:
144 seconds
Step-by-step explanation:
To do solve this question, we must find the LCM (least common multiple) of 12, 16, and 18.
Let's start by prime factorizing (finding the prime factors) all the numbers.
[tex]12\rightarrow3*4\rightarrow2*2*3[/tex]
[tex]16\rightarrow4*4\rightarrow2*2*2*2[/tex]
[tex]18\rightarrow2*9\rightarrow2*3*3[/tex]
Now, we must find the greatest quantity of each [prime] number and multiply them together to obtain the least common multiple.
Upon further evaluation of the [prime] factors, we can see that we need four 2s and two 3s. Therefore...
[tex]2*2*2*2*3*3=2^4*3^2=16*9=144[/tex]
They will be fired together again after 144 seconds.
