Interesting - The face down cards problem...

[imhotep]

As shown in this movie clip there are 20 cards placed in a row, all face down. Now select one face down card and turn it over, but the card right to it has to be turned over too. Then go onto another face down card and repeat the same procedure. What the problem says is that after a number of operations, eventually all cards will end up being face up.
Note that this is going to be valid for any number of cards...
Nathan provides an elegant solution.... Can anyone think of an alternative?

 

[hodakolla]

BUMPER

 

[PHBhagya]

අන්තිම ටික තේරුණේ නෑ...
මැද කාඩ් අට ෆේස් අප් වුණාමත්,
දෙකෙලවරේ ෆේස් ඩවුන් කාඩ් දෙකක් ඉතිරිවෙනවනෙ.

Edit- හරි හරි... ඒකනෙ වෙන්න ඕනෙ.

 

[imhotep]

අන්තිම ටික තේරුණේ නෑ...
මැද කාඩ් අට ෆේස් අප් වුණාමත්,
දෙකෙලවරේ ෆේස් ඩවුන් කාඩ් දෙකක් ඉතිරිවෙනවනෙ.

Edit- හරි හරි... ඒකනෙ වෙන්න ඕනෙ.

It should work for any number cards....Whenever you turn a card, the next card on the right hand side needs to be turned over. Obviously in the row, the card in the extreme right end does not have a next one to turn over.
(But the leftmost card always has a card next, right to it)