Jump to content
BrainDen.com - Brain Teasers
  • 0


Guest

Question

:rolleyes:So, you are blindfolded and wearing thick gloves, and someone put twenty coins on the table. Ten of them are on heads and ten of them are on tails, but you wouldn't know which because of your blindfold and gloves. You could flip or move the coins if you want. Your goal is to group them into two with ten coins each. The two groups should have the same number of heads and the same number of tails. How do you do it?
Link to post
Share on other sites

19 answers to this question

Recommended Posts

  • 0

Randomly divide them into 2 groups of 10 each.

Now if the first group has X tails, then it has (10-X) heads. This implies also that the second group has (10-X) tails and X heads. Now simply flip all the coins in one of these groups and you have the desired result: same number of heads and tails in each.

Link to post
Share on other sites
  • 0

I would just take the blindfold off!

Randomly divide them into 2 groups of 10 each.

Now if the first group has X tails, then it has (10-X) heads. This implies also that the second group has (10-X) tails and X heads. Now simply flip all the coins in one of these groups and you have the desired result: same number of heads and tails in each.

Link to post
Share on other sites
  • 0

Arrange the coins into 2 random groups of 10. In each group of 10, each coin has one head, one tail. No matter how you arrange the coins, there will be 10 heads and 10 tails in each group. The instructions don't specify that you should count only the side of the coins facing up.

Link to post
Share on other sites
  • 0

Since you start off with half the coins on tails and half on heads; you can randomly divide them into two piles of 10 and each set of ten will be the compliment of the other set of 10. i.e. if you randomly take 10 coins that happen to contain 3 tails and 7 heads, the other pile will have to have 3 heads and 7 tails. Therefore the solution is to just take any 10 coins and flip them over. They will then be just like the 10 coins you didn't flip over.

Link to post
Share on other sites
  • 0

Arrange the coins into 2 random groups of 10. In each group of 10, each coin has one head, one tail. No matter how you arrange the coins, there will be 10 heads and 10 tails in each group. The instructions don't specify that you should count only the side of the coins facing up.

early,

The instructions don't explicitly prevent one from removing the blindfold either, but there are certain assumptions one can make.

I was thrown by one assumption I made that perhaps I should NOT have made. I thought the goal was to end up with an EVEN number of heads and tails IN EACH GROUP, whereas the idea of having the same number of heads in each group, and the same number of tails in each group, is a more solvable puzzle.

Link to post
Share on other sites
  • 0

:rolleyes:So, you are blindfolded and wearing thick gloves, and someone put twenty coins on the table. Ten of them are on heads and ten of them are on tails, but you wouldn't know which because of your blindfold and gloves. You could flip or move the coins if you want. Your goal is to group them into two with ten coins each. The two groups should have the same number of heads and the same number of tails. How do you do it?

Link to post
Share on other sites
  • 0

Hi

I am new

I do not have an answer

but how do I receive the solution.

TXS

Robsbrain

Hi Robsbrain.....welcome to the den!

Sometimes, puzzles go unanswered for quite a while (Peace*out has had 1 on the go since last June!), but quite often they're solved fairly quickly. If you really want to know the answers, click on the spoiler "show" button to reveal what people have guessed. (Their guesses aren't necessarily correct, btw!)

Edited by fabpig
Link to post
Share on other sites
  • 0

Hi

I am new

I do not have an answer

but how do I receive the solution.

TXS

Robsbrain

Hi Rob,

Welcome to BrainDen. The idea of this forum is that you have to work it out ;)

If your brain isn't working today, you might get the answer by clicking the box labelled "Show" after the words "Spoiler for ..."

I hope this helps you.

Cheers,

Tony

Link to post
Share on other sites
  • 0

similar post of sent a month before,whatever

first take 10 coins out as it is and now reverse every coin in the another pile you will have same no of coins with heads in each pile

I know the answer but I can't understand it's working

Can anyone HELP!!

Edited by Shivam
Link to post
Share on other sites
  • 0

..it says u must have exact number of heads and tails in each group...which means both groups must have 5 heads and 5 tails or 7 heads and 3 tails in both gropus...hm..my thinking time is over..but Im still trying to understand how to divide them..what if there are all tails or head?....

hi Im new here...trying to activate my brain a little bit...

Edited by Nano7
Link to post
Share on other sites
  • 0

soryy in my 1. gusssing spoiler I have some misstakes...only thing true is that both gropus need 5 heads and 5 tailis.. the other stuff is nonsence...Im still trying to divde them...lol..this will take some time....

Link to post
Share on other sites
  • 0

The answer was you divide them randomly into two groups. Then you flip every coin on the other side because if you had 6 heads 4 tails on one side, you have 4 heads 6 tails on the other. Flipping everything on the other side, you would have 6 heads on both and 4 tails on both. That is true for all combination like 5 and 5, 7 and 3, 8 and 2, 9 and 1, 10 and 0. Hope this is clear to you!

enrightmcc, Shivam, and Adhish Majumdar all got it right :thumbsup: !

Thanks, Smith!

:lol: thanks too for the other funny answers.

Welcome, Robsbrain!

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...