Alarm clock
The old watchmaker has a unique digital alarm in its collection that rings whenever the sum of the alarm's digits equals 21. Find out when the alarm clock will ring. What is their number? List all options.
Final Answer:

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Do you want to convert time units like minutes to seconds?
Would you like to compute the count of combinations?
Do you want to convert time units like minutes to seconds?
Would you like to compute the count of combinations?
You need to know the following knowledge to solve this word math problem:
combinatoricsbasic operations and conceptsnumbersUnits of physical quantitiesthemes, topicsGrade of the word problem
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