A bookshelf contains 9 mysteries, 7 biographies, and 4 science fiction books. A book is randomly selected, not replaced, then another is selected. Find the probability of selecting a biography then a mystery.
20*19 = 380, not 320
so far, so good. The probability of getting both books is
7/20 * 9/19
You have 20 books.
The chance of getting a biography is 7/20
Not replaced so now you have 19 books
mystery would be 9/19
You have to multiply 7/20 times 9/19 to get the probability of selecting a bio then a mystery book. I don't know if your teacher wants the answer in fraction or decimal form.
Oh i forgot to put what I think. Is it 7/20 because it's 20 total books and only 7 of them are biographies?
A bookshelf contains 9 mysteries, 7 biographies, and 4 science fiction books. A book is randomly selected, not replaced, then another is selected. Find the probability of selecting a biography then a mystery.
A bookshelf contains 9 mysteries, 7 biographies, and 4 science fiction books. A book is randomly selected, not replaced, then another is selected. Find the probability of selecting a biography then a mystery.
Give answer as a fraction in simplest form.