# Lil's Dead Giveaway Trick!

This is one of the many tricks that Riverboat Lil plays in the Last Chance Saloon to win money. It looks like a game that the customer cannot lose, but they always do!

• You need seven playing cards: four BLACK and three RED. You shuffle them up and put them face down on the table.
• The customer starts with £100. Everytime he plays he must bet half his money.
• The customer turns over the first card.
If the card is BLACK he wins his bet.
If the card is RED he loses his bet.
• Keep going. All seven cards must be played and the customer must bet half his money each time. ( Numbers can be rounded up or down to the nearest £1, it doesn't affect the trick much.)
• Obviously the customer will win four times and only lose three times. Therefore it looks like he should end up winning!
• After the 7th card is played, the customer will be left with about £63 out of his £100. You will have won about £37.

#### EXAMPLE GAME

 Customer starts with £100 so he bets £50 CARD 1 = BLACK Customer wins! Total money = £100 + £50 = £150 Customer has £150 so he bets £75 CARD 2 = RED Customer loses! Total money = £150 - £75 =£75 Customer has £75 so he bets £37 CARD 3 = BLACK Customer wins! Total money = £75 + £37 = £112 Customer has £112 so he bets £56 CARD 4 = RED Customer loses! Total money = £112 - £56 = £56 Customer has £56 so he bets £28 CARD 5 = BLACK Customer wins! Total money = £56 + £28 = £84 Customer has £84 so he bets £42 CARD 6 = BLACK Customer wins! Total money = £84 + £42 = £126 Customer has £126 so he bets £63 CARD 7 = RED Customer loses! Total money = £126 - £63 = £63

The customer will always lose, regardless of what order the seven cards appear!

#### HOW DOES IT WORK?

Look at what happened in the example after the first two cards. The customer won one and lost one, but instead of ending with his £100 back, he was already down to £75. If the two cards had appeared the other way round he would have first lost (£100 - £50 = £50) and then won (£50 + £25 = £75) and still have finished with £75.

A BLACK card has the effect of multiplying the current total of money held by 3/2.

A RED card has the effect of multiplying the current total of money by 1/2.

The game offers four BLACKS and three REDS, so the final fraction of money left will be (3/2)4 x (1/2)4 = 81/128 = about 63%. So if the player starts with £100, he will only finish with about £63 regardless of what order the cards are picked.

If you like this then try The Red and Black Mystery!

 This trick and many others appear in Brainbenders

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