Solution to Puzzle 7 and 8

[kunal naidu]

Q. You are blindfolded and are sitting in front af a table. On the table are many coins. Out of them, you are told that exactly 26 coins have "heads" facing up. Now you have to divide the coins into 2 groups such that both groups have the same number of coins having "heads" facing up. You cannot find out the side of the coin by feeling it with your fingers. Devise a strategy for this

Solution: Divide the coins into two groups, one of the groups having 26 coins and the other group having the rest. Now flip over all the coins in the 26 coin group. you will now have equal number of heads in the 2 groups!!!

Q. A person is under medication of pills A and B. He needs to take one pill each, everyday to survive. If he does not take one pill each, everyday, he will die. Also, if he takes more than one pill of the same type any day, he will die. He has a bottle each for the 2 types of pills. Now the 2 types of pills look exactly alike. While taking the pills out of the bottle, he accidently drops 2 pills of type B and one of pill A on the table. Now, the man does not know which pill is type B and which is type A since they look alike. He is poor and cannot afford to throw the pills away. Can you find a way by which he will be able to take his medication that day, without any wastage and without any dire consequences.

Solution: Add another pill A onto the table. Now you have 2 pill A and 2 pill B on the table. Now, break each pill into half and keep the 2 parts in two separate groups. Do this for all the 4 pills. Now you will be left with 2 groups of pills, each group having 2 halves of pill A and 2 halves of pill B, i.e. 1 pill A and 1 pill B!!!!

[Deepak]

i dint get the first one 

[Subodh Malgonde]

@deepak:

lets say you have 26 heads and x tails on the table

Now when you randomly pick 26 coins from the table, lets us say it has y heads and 26-y tails. The remaining coins will have 26-y heads and some tails(which are irrelevant over here). Now when you flip the group of 26 coins it will have 26-y heads and y tails.

[kunal naidu]

nicely explained subodh