Question 1. Score: 0/11
X
p(x)
?
2
3/37
3
1/37
4
1/37
5
0/37
6
1/37
In the top 50 most played Spotify songs one day, there are 37 unique albums. Let X = # of times an album
appears on the top 50 list
a) What is p(1)?
b) If the total length of all 50 songs is 155 minutes and in order to listen to all these songs in Spotify, you
have to listen to 8 ads in total, where the expected value for an ad is 3/4 minute, then what is the
expected amount of time it will take you to listen to all 50 songs?
c) If the total length of all 50 songs is 155 minutes and in order to listen to all these songs in Spotify, you
have to listen to 8 ads in total, where the standard deviation for an ad is 1/3 minute, then what is the
standard deviation for the time it will take you to listen to all 50 songs?
Score: N/A/3.667 N/A/3.667 N/A/3.667
Question 2. Score: 0/4
Say that a hacker group is trying to break into the company website of Doofenshmirtz Evil Incorporated.
They know that the password is 8 characters. Valid characters are
The 26 capital alphabet letters A-Z
The 26 lowercase alphabet letters a-z
The 10 numbers 0-9
And also the 8 special characters !@#$%^&*
If you know that 3 characters are different lowercase letters, and 2 are different numbers, and the rest are
the other kinds of symbols, how many passwords are possible?
Score: N/A/4