There are 20 C3 possible ways to choose 3 books to read.
There are 5 C3 possible ways to choose 3 mysteries to read.
The probability that Mariah will not choose all mysteries can be expressed as 1-5C3/20C3. (These 3 Choices Are True)
There are 1 C3 possible ways to choose 3 books that are not all mysteries.
The probability that Mariah will choose 3 mysteries can be expressed as 1/5C3.
(These 2 Choices Are False)
Hope This Helps
Shelters found for dogs = 12,308
Shelters found for cats = 7,953
Total number of shelters found
= Shelters found for dogs + Shelters found for cats
= 12,308 + 7,953
= 20,261 shelters
Therefore, the total number of shelter found for both dogs and cats last year is 20,261 shelters
