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Penny Problem (Posted on 2003-10-14) Difficulty: 3 of 5
You are blindfolded before a table. On the table are a very large number of pennies. You are told 128 of the pennies are heads up and the rest are tails up.

How can you create two subgroups of pennies, each with the same number of heads facing up?

See The Solution Submitted by Ravi Raja    
Rating: 3.7500 (16 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
A visual solution (short) Comment 18 of 18 |
Suppose there are 1028 tails,
128 heads
1028 tails

divided, with left pile of 128. There are 128 heads, and 128 on the left pile, so it doesn't matter how many heads happen to be in the left pile (suppose 100)
100   28 heads
28     1000 tails

Turn over the left pile
28      28 heads
100    1000 tails

The supposed numbers don't affect the problem. The numbers can be changed, but each pile will still have the same number of heads

Edited on June 15, 2008, 9:32 pm
  Posted by Gamer on 2008-06-15 21:31:20

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