Nice easy one for ya ......

[Gizmonster]

80 cards are laid out on a table in a single file.
All of the cards are blank on one side and have a number on the other.
All of the cards are face up - i.e. the value of the number is shown.

You now play a game against one other person. You each take it in turns to remove 1 card at a time.
You can only remove a card from either end of the line of cards - you cannot remove a card from somewhere in the middle. So, for example, if you remove card no 1, your opponent can only remove card 2 or 80. Or, if you remove card no 80, your opponent can only remove card 1 or 79.
At the end of the game, you'll both have 40 cards (obviously!!) - the winner is the one who's sum of all the values on the cards is the greatest.
You get to choose first, so what strategy should you employ to ensure that you never lose ???

[mike11111]

Please reread my post carefully, I have divided by 2 at the end.

[mike11111]

Oh, I see what you mean, divide by 2 after using the formula. Yes, sorry.