Easy Probability Question

  • Thread starter succubus
  • Start date
  • #1
33
0
A set of 1000 cards, numbered 1 through 1000 are distributed among 1000 people. Compute the expected number of cards that are given to people whose age matches the number on the card.


So the relevant formula is expected value, but its conditioned because of the ages. So I assumed that the age range was between 1-100.
So n* P{card reads age | age <= 100)

Is this the correct assumption?

So would the probability be 1/1000 / 100/1000 = .01
 

Answers and Replies

  • #2
392
0
The answer is 1.

Hints:

Consider the random variable N_i = number of people age i who get a card with their age.

We want E(N_1 + N_2 + ... + N_1000).
 

Related Threads on Easy Probability Question

Replies
4
Views
1K
Replies
7
Views
2K
Replies
2
Views
2K
  • Last Post
2
Replies
34
Views
2K
Replies
7
Views
9K
  • Last Post
Replies
3
Views
776
  • Last Post
Replies
3
Views
1K
Replies
1
Views
2K
Replies
5
Views
979
  • Last Post
Replies
1
Views
1K
Top