1. Apr 19, 2009 #1

   succubus

   

   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

    

   succubus, Apr 19, 2009
2. 
   Phys.org - latest science and technology news stories on Phys.org

   • • Game over? Computer beats human champ in ancient Chinese game
   • • Simplifying solar cells with a new mix of materials
   • • Imaged 'jets' reveal cerium's post-shock inner strength
3. Apr 20, 2009 #2

   Billy Bob

   

   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).

    

   Billy Bob, Apr 20, 2009

• Log in with Facebook
• Log in with Twitter

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in