Question 1133209: Since this question has an image, I'll post on in this link
https://imgur.com/a/0rV2aw8
I don't understand the actual answer in this question. Is there some concept to be learnt to answer this question?
Answer by greenestamps(13198)   (Show Source):
You can put this solution on YOUR website!
Let's imagine a clock face and call the initial position of X and Y 3 o'clock.
X moves counterclockwise at 1 revolution every 4 seconds, or 90 degrees per second. So the times that X is at different places are the following:
3 o'clock: 0, 4, 8, 12, 16, ...
noon: 1, 5, 9, 13, 17, ...
9 o'clock: 2, 6, 10, 14, 18, ...
6 o'clock: 3, 7, 11, 15, 19 ...
Y moves counterclockwise at 1 revolution every 6 seconds, or 90 degrees every 1.5 seconds. So the times that Y is at different places are the following:
3 o'clock: 0, 6, 12, 18, 24, ...
noon: 1.5, 7.5, 13.5, 19.5, 25.5, ...
9 o'clock: 3, 9, 15, 21, 27, ...
6 o'clock: 4.5, 10.5, 16.5, 22.5, 28.5, ...
Now look at the answer choices. Answer A has X and Y both at noon at the same time. Are there any times in the lists above when both X and Y are at noon? No. So A is not the answer.
Checking the other answer choices in the same way, you should see that answer choice C is the only one that shows possible positions of X and Y at some future time.
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