Question 1025726
For each character of the 7-character password there can be 
a different letter or number.
26 letters + 10 digits = 36
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The 1st character can be 36 possible 
There are no repetitions, so there are
35 possible for 2nd character
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This continues for 7 characters, so
{{{ 36*35*34*33*32*31*30 = 42072307200 }}}
possible passwords
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Hope I got it -you can get other opinions too