All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars
 perplexus dot info

 Odds are ... (Posted on 2017-02-14)
You face an urn with 5555 cards in it, each has a non-zero integer written on it. Nothing is said about the distribution of those numbers. You are told to draw randomly a card, copy the number, return it back, shuffle and draw randomly a card, then write down the sum of both numbers, say S.

(i) Prove: The probability of S being an even number is higher than S being odd.
(ii) Is it true for any initial number of cards? Comment.

Comments: ( Back to comment list | You must be logged in to post comments.)
 re: A related problem which resolves part 2. | Comment 7 of 8 |
(In reply to A related problem which resolves part 2. by Brian Smith)

It is a different problem:

- the second draw is after returning 1st card
- nothing is known about the distribution of the numbers

 Posted by Ady TZIDON on 2017-02-14 17:37:38

 Search: Search body:
Forums (0)
Random Problem
Site Statistics
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox: