Question

Josh types the 5 entries in the works cited page of his term paper in random order, forgetting that they should be in alphabetical order by author. What is the probability that he actually typed them in alphabetical order?

Answer 1

0.83% probability that he actually typed them in alphabetical order.

Explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

The number of ways in which n terms can be arranged is given by:

`A_(n) = n!`

Desired outcomes:

Only one outcome in which the five entries are in alphabetical order, so
`D = 1`.

Total outcomes:

We want to arrange 5 entries. So

`T = A_(5) = 5! = 120`

Probability:

`p = (D)/(T) = 0.0083`

0.83% probability that he actually typed them in alphabetical order.