The both lights will blink same at 20 seconds.
What is least common multiple?
LCM stands for Least Common Multiple. It is the common multiple of lowest degree of two or more polynomials. A factor is one of the numbers that multiplies by a whole number to get that number.
For the given situation,
A green light blinks every 4 seconds and
A yellow light blinks every 5 seconds.
Both lights blink at the same time can be found by taking LCM for both the time.
The factors of 4 = [tex]1,2,4[/tex]
The factors of 5 = [tex]1,5[/tex]
Now the LCM of 4 and 5 = [tex](4)(5)[/tex]
⇒ [tex]20[/tex]
Hence we can conclude that the both lights will blink same at 20 seconds.
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