Question

How many five character strings we can made by using three lower case letters and two digits?

Answer 1

Answer:

Explanation:

1

Given that you can have 5 letter password that contains either lowercase or uppercase. My questions are: 1) How many possible passwords are there?

I did 525=380,204,032 since there are 52 letters, 26 lower and 26 upper.

2) How many possible passwords are lowercase only?

265 = 11,881,375 since there are only 26 lower

3) How many possible passwords are uppercase only?

265 = 11,881,375 since there are only 26 upper

4.) How many possible passwords are there that uses at least 1 uppercase and 1 lowercase?

Not sure about this one...

Answer 2

Explanation:

6.1.16 [2 points] How many strings are there of four lowercase letters that have the letter x in them? There are 264 strings in all and 254 that do not have the letter x. Thus there are 264 - 254 = 66351 that have the letter x.