Flipping two coins at a time
There are 4 coins in front of me, three of them showing heads and the other one tails.
If I want all of them to show heads, I just have to turn the last coin over.
Can I still pull off this feat if I'm only allowed to turn over any 2 coins simultaneously as many times as I want?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
If you have 3H and 1T, and you flip any two over, you will still be left with a 3,1 formation.
For example, if you flip any two H, you'll be left with 3T and 1H (3,1)
Or, if you flip a H and a T, you'll be left with 3H and 1T (3,1)
That means, that no matter what you do, a 3,1 formation on flipping any 2 coins will turn into a 3,1 formation only, hence a 2,2 formation can never be obtained.