Find all integers n such that when the clock strikes n o'clock, the acute angle between the hour and minute hands is 90 degrees. Enter your answer as a comma-separated list.
< Find all integers n such that when the clock strikes n o'clock, the acute angle between the hour and minute hands is 90 degrees. Enter your answer as a comma-separated list. >
Note that 90o is not an acute angle, but never mind that. When the clock strikes the hour, that means the minute hand is on the 12. For the angle to be 90o the hour hand must be on either the 3 or the 9. Assuming a 12-hour clock.
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