You have two bottles of pills marked with the label A and B. The pills are identical. The doctor has asked you to take one A pill and one B pill daily. You cant take more or less than that.
While taking out the pills one day, you took out one pill from A and by mistake took out two from B. You have no idea which pill is which now.
You cant throw away the expensive pills. What will you do now?
Cut each of the three pills in half and put each half in two piles. Now, each of the two piles will contain half of pill A and two halves of pill B.
Take one pill A and cut into half and put the two halves in the two piles. Now, each pile will have two halves of pill A and two halves of pill B which means one pill A and one pill B. You can take one pile today and one pile the next day.