## Search This Blog

### The Cards Magic Riddle

The Cards Magic Riddle - 21 February

David Blaine and Dynamo performed together in our college fest. I was chosen to be performed a card trick on. Blaine asked me to shuffle a deck of cards and when I was done, he asked me to pick any five cards. I did as he had asked and showed my selected cards to Blaine.

Out of those five cards, he gave four to Dynamo and one back to me. Upon looking at those four cards, he was able to deduce the card I was holding.

I was shocked. It was brilliant. But when I was returning back home, I thought about it and was able to crack the trick.

Do you know how they did it?

#### 1 comment:

1. The five cards must contain at least one card of the same suit.
Let's assume Blaine placed one of the two cards of the same suit at the end and the second card was given to Dynamo.
In that case, Dynamo will know the suit of the card.

Now the real question is how Blaine made sure that Dynamo also knows the number of the card.

Dynamo got four cards and one of them will determine the suit, so we are left with 3 cards.
3 cards can be arranged in 3! ways i.e. 6 ways but our card numbers can vary from 1 to 13.
Since we have two cards of the same suit we will make sure that we don't pick the King (13). This leaves us with 12 numbers.

We can also distinguish card from upside down position, therefore, we now have 6 * 2 ways to arrange these card.
"TADA.... We cracked the magic trick".

Let us assume that the smallest card is C1U (upwards position) and C1D (downwards position). Similarly, we have C2U, C2D, C3U and C3D

According to that, the 12 possible arrangements are:
C1U C2U C3U => NUMBER 1
C1U C3U C2U => NUMBER 2
C2U C1U C3U => NUMBER 3
C2U C3U C1U => NUMBER 4
C3U C1U C2U => NUMBER 5
C3U C2U C1U => NUMBER 6
C1D C2D C3D => NDMBER 7
C1D C3D C2D => NDMBER 8
C2D C1D C3D => NDMBER 9
C2D C3D C1D => NDMBER 10
C3D C1D C2D => NDMBER 11
C3D C2D C1D => NDMBER 12

Please note that king (number 13) is not possible as discussed already.