0

# I need help with a riddle

Fri 6 Jan, 2012 07:33 am
I cannot seem to get this riddle, after giving up I finally googled it, and the answer I found there does not seem to make sense to me.

Thank you.

You have 50 quarters on the table in front of you. You are blindfolded and cannot discern whether a coin is heads up or tails up by feeling it. You are told that x coins are heads up, where 0 < x < 50. You are asked to separate the coins into two piles in such a way that the number of heads up coins in both piles is the same at the end. You may flip any coin over as many times as you want. How will you do it?
• Topic Stats
• Top Replies
Type: Question • Score: 0 • Views: 1,038 • Replies: 2
No top replies

fresco

1
Fri 6 Jan, 2012 08:31 am
@Xazy,
BM
0 Replies

fresco

1
Fri 6 Jan, 2012 08:59 am
@Xazy,
Divide the coins into two piles A and B with x coins in A.
If there are p heads in A then there are x-p tails in A
But there are x-p heads in B, so turn all of A over so that its tails become heads, giving x-p heads as in B.
Remember x is just the starting number of heads.

Example: Suppose x=10, p=3
A=(3H,7T) B=(7H, 33T).Turn A over giving new A=(7H,3T)
0 Replies

### Related Topics

Christmas Math - Question by libertydawn
the soldier - Question by coacoa09
Marbles in a Bag - Riddle - Question by Valedictum
Sneaky Sequences - Question by Rainy
BOXES AND BOXES - Question by Valedictum
How does the driver know to swerve - Question by jboogy
... - Question by britney-brendan
small riddle - Question by tomtom1996
Can anyone solve this riddle? - Question by zezima63

1. Forums
2. » I need help with a riddle