988 B
988 B
id | title | challengeType | forumTopicId |
---|---|---|---|
5900f4e01000cf542c50fff2 | Problem 371: Licence plates | 5 | 302033 |
--description--
Oregon licence plates consist of three letters followed by a three digit number (each digit can be from [0..9]).
While driving to work Seth plays the following game:
Whenever the numbers of two licence plates seen on his trip add to 1000 that's a win.
E.g. MIC-012 and HAN-988 is a win and RYU-500 and SET-500 too. (as long as he sees them in the same trip).
Find the expected number of plates he needs to see for a win. Give your answer rounded to 8 decimal places behind the decimal point.
Note: We assume that each licence plate seen is equally likely to have any three digit number on it.
--hints--
euler371()
should return 40.66368097.
assert.strictEqual(euler371(), 40.66368097);
--seed--
--seed-contents--
function euler371() {
return true;
}
euler371();
--solutions--
// solution required