Answer:
1000 Hz
Step-by-step explanation:
Data provided in the question: 
Number of times the signal is repeated = 60,000. 
Time taken for 60,000 repetition = 1 minute = 60 seconds.
Now,
The Frequency is given as the Number of cycles repeated per second
Therefore, 
For the given data
Frequency = [ 60,000 ] ÷ [ 60 ]
or
Frequency = 1000 Hz