[algogeeks] Re: no. of passwords

2011-02-09 Thread SVIX
ah... I see what you're saying... On Feb 9, 8:56 pm, Dave wrote: > @SVIX: According to my calculation, this gives > 2,992,430,052,218,880,000, almost 12 times the correct answer, > 251,471,033,958,144,000, that I gave earlier in > postinghttp://groups.google.com/group/algogeeks/msg/bb2269736a997

[algogeeks] Re: no. of passwords

2011-02-09 Thread Dave
@SVIX: According to my calculation, this gives 2,992,430,052,218,880,000, almost 12 times the correct answer, 251,471,033,958,144,000, that I gave earlier in posting http://groups.google.com/group/algogeeks/msg/bb2269736a997419. This is because you are counting some passwords multiple times. Consid

[algogeeks] Re: no. of passwords

2011-02-09 Thread SVIX
1. there should be atleast 3 capital letters 2. atleast 3 small letters -> 6 spaces gone for these, with repetitions allowed. for 3 spaces, we have 26^3 possibilities, and they can be arranged in 10C3 ways... for the next 3, they can be arranged in 7C3 ways 3. atleast 2 numbers 0-9 now, 4 spac

[algogeeks] Re: no. of passwords

2011-02-09 Thread Dave
No. That is too large, at 2,087,438,895,360,000,000. Analyzing your expression, 26C3 is the number of ways to choose 3 different letters, but the letters can be the same. The number of combinations of 3 letters with repetitions is 26^3. So that aspect of your formula is too small. However, you can'

[algogeeks] Re: no. of passwords

2011-02-09 Thread Dave
The following combinations of capital letters "C", lower case letters "l", and digits "d" are possible: C l d Number possible 3 3 4 10C3 * 26^3 * 7C3 * 26^3 * 4C4 * 10^4 3 4 3 10C3 * 26^3 * 7C4 * 26^4 * 3C3 * 10^3 3 5 2 10C3 * 26^3 * 7C5 * 26^5 * 2C2 * 10^2 4 3 3 10C4 * 26^4 * 6C3 * 26^3 * 3C