Answer:
10,000
Step-by-step explanation:
With a bike lock, you can usually use the same number more than one... you can have them the same (7777) if you want.
So, you have 10 possibilities for the first digit, 10 again for the second digit, 10 for the third digit... and also 10 for the last digit. So...
10 * 10 * 10 * 10 = 10,000
These combinations range from 0000 to 9999
