So, if the two signals change simultaneously now, again they will change simultaneously after 12 seconds. This 12 is the least common multiple (LCM) of 3 and 4. The same thing happened in our problem. To find the time, when they will all change simultaneously, we have to find the LCM ...
and greatest common divisor(gcd) . hcm and lcm are two different methods, where lcm or least common multiple is used to find the smallest common multiple of any two or more numbers. table of contents: definition how to find by prime factorization by division method by shortcut method hcf ...