Please Help!! How many 3-digit codes using the digits 0-9 are possible if repetitions are allowed?

Question

anonymous · Answer

Thank you

anonymous · Answer

But how did you know what to multiply?

anonymous · Answer

Ok, just getting into that now. Thank you

anonymous · Answer

Luis Rivera's answer seems incorrect (as repetition is allowed) the correct answer is $ 9 \times 10 \times 10 = 900 $.

zarkon · Answer

are leading zeros permitted?

anonymous · Answer

I assumed leading zeros are not permitted since in general sense that will not be a 3 digit number.

zarkon · Answer

but it says 3 digit code not 3 digit number

zarkon · Answer

if you allow leading zeros then there are $10^3=1000$ possibilities

anonymous · Answer

Okay, if the leading zero is allowed then you have to add 100 more numbers to the previous 900.

anonymous · Answer

$$ 10 \times 10 \times 10 $$

zarkon · Answer

@Luis Rivera
?

anonymous · Answer

Yes, that last comment doesn't make any sense.