A secretary has typed N letters along with their respective envelopes. The envelopes get mixed up when

Question:

A secretary has typed N letters along with their respective envelopes. The envelopes get mixed up when they fall on the floor. If the letters are placed in the mixed-up envelopes in a completely random manner (that is, each letter is equally likely to end up in any of the envelopes), what is the expected number of letters that are placed in the correct envelopes?

Fantastic news! We've Found the answer you've been seeking!

Step by Step Answer:

Question Posted: