Answer:
The number of ways she can choose four albums for display with at least two from Diana Kroll is from the sixteen albums is 665 ways
Step-by-step explanation:
1) The number of ways she can choose 2 albums of Diana from the 5 Diana Kroll albums is 5!/(2!(5 - 2)!) = 10 ways
Choosing the other 2 albums from the remaining 11 albums gives;
11!/(2!(11 - 2)!) = 55 ways
Total number of ways is then 10 × 55 = 550 ways
Choosing 3 from the 5 Diana Kroll albums is 5!/(3!(5 - 3)!) = 10 ways
Choosing the other 1 album from the remaining 11 albums gives;
11!/(1!(11 - 1)!) = 11 ways
Total number of ways is then 10 × 11 = 110 ways
Choosing 4 from the 5 Diana Kroll albums is 5!/(4!(5 - 4)!) = 5 ways
Choosing the other 0 album from the remaining 11 albums gives;
11!/(0!(11 - 0)!) = 1 way
Total number of ways is then 5 × 1 = 5 ways
Total number of ways = 550 + 110 + 5 = 665 ways
2) In the indirect method, we first find the number of ways to choose 4 albums out of the 16 albums, then we subtract the number of cases where there are 1 and 0 Diana Kroll albums as follows;
16!/(4!(16 - 4)!) = 1820 ways
With 1 Diana Kroll album gives
5!/(1!(5 - 1)!)×11!(3!(11 - 3)!) = 825 ways
With 0 Diana Kroll album gives
5!/(0!(5 - 0)!)×11!(4!(11 - 4)!) = 330 ways
Total number of ways with at least 2 Diana Kroll albums = 1820 - 825 - 330
Total number of ways with at least 2 Diana Kroll albums = 665 ways.
