Sunday, June 24, 2007


You have two boxes full of pills.
- Box A contains pills of type "A"
- Box B contains pills of type "B"

Both Box A and Box B have equal number of "A" pills and "B" pills respectively.

The "A" pills and the "B" pills are physically identical and one cannot differentiate between them.

You are supposed to take one "A" pill and one "B" pill everyday exactly .
Any other combination ( AA, BB or just A or just B) will have disastrous side effects.

One day, you take one pill from Box A in your hand, and accidentally 2 "B" pills falls on your hand. (So your hand has the pills A, B,B ) and these are indistinguishable from each other.

How will you avoid any disastrous side effects ?

PS :- Found this on Outlook (the magazine) this month. :-)


sarvagnaani said...

some stupid answers :D

since the pills are physically indistinguishable..dont try to do that..we have to ensure no side effects..
soo..add one more pill from A, now u have balanced set of pills in your hand.If taking an extra 'piar' of pills is no issue, the prob is solved. Simply take 4 pills instead of 2.
Otherwise, powder the pills and mix them well. Divide the mixture into 2 equal parts. Consume one today and the remaining tomorrow. This assumes that the pills can be mixed in room temp outside human body and that will not result in any blast :p

sudeep said...

The last solution is definitely innovative dude...

richie said...

Discard the 3 pills. Take 2 new ones from box A and B respectively.

Play safe :).

sudeep said...

Richie, your solution is not acceptable because, I forgot to mention one constraint....

The subscription has to be taken for "x" number of days only. Where "x" is the number of pills in Box A and Box B.

If it is not taken, for x days, the side effects will start !!!!

Solution :-

1] Take out an A pill from the box A.

2] Add an A pill to the 3 "unknown" pills (A,B,B).

Split all pills into halves. Then separate the halves in the direction of the split.

(If you have placed all the pills along a straight vertical line, the halves will be left half and right half....If you have split the pills along a straight horizontal line, the halves should be separated as up-half and down-half).

3]Since there are 2 A and 2 B pills, you get 1 A and 1 B each day.