help

A number from 100 to 999, inclusive, is chosen at random.  What is the probability the number contains a digit of 0?

 

There are 999-100+1 = 900 numbers here

You have to work out how many of those have at least one 0.

All the ones that end in 0 have a 0  How many of those are there?

All the ones that have 0 in the middle have a 0.  How many of those are there?

 

You could add those together but the trouble is that you will have included all the ones with two zeros twice.

So you need to work out how many have 2 zeros and subtract that answer.

 

Now you can do at least some of this question by yourself and then you can ask questions if you want to.

 

Please no one diminish the value of my teaching answer by answering over me.