Answer:
1.5
Step-by-step explanation:
First congratulations, Oneli. I checked you have put up a few questions and a few answers - that makes you an ACTUAL Quora user, rather than a question mill operator!
Next, I have to decide what you meant by “swing”. That could mean a displacement from one extreme to the other, or what clock-makers call a “beat” - or quite possibly you meant what engineers and scientists call a “cycle” Which means a swing from left to right, then back from right to left again,
In this question, it doesn’t really matter if I guess your meaning correctly though: your question said in essence:
given the time for twenty somethings, what is the time for ONE something.
As soon as you visualize this, I hope you can see that one something takes 1/20 of the time for 20 somethings. So far, so good; what IS the time for 20 somethings?> 30 seconds, of course! So we want 1/20 of 30 seconds = 30 / 20 = 3/2 = 1.5 seconds..