how many possible 3 digit numbers are there that have a middle zero? how many possible 4 digit numbers are there that have 2 middle zero? explain your answear
In both cases, the zeros are constant. The first number can vary 1-9 (since 00x or 000x are not numbers), while the last number can vary from 0-9. Thus there are 9 possibilities for the first number and 10 for the last.
You should be able to take it from here.
I hope this helps. Thanks for asking.