The guessing game story reminded me of an interesting but uncommon puzzle that was posed to us by one of our teachers. I am grateful to him as I found it handy during hundreds of hiring interviews that I had to take, many years later, where I needed a less known puzzle.
This is how my narration of the puzzle goes…
Look at the picture. As you see, it is a picturesque (if we condone my drawing skill for a moment) place with three temples and a well in front of each of them and a flowering plant near the entrance.
A person enters the place, plucks a certain number of flowers from the plant, and goes to the first temple. Before entering the first temple she dips all the plucked flowers into the well in front of it. With the magical powers of the water, the number of flowers gets doubled. She goes and offers a certain number of those flowers inside the first temple.
She goes and dips all the remaining flowers into the second well and the flowers get doubled, again. She goes inside the second temple and offers again the same number of flowers as many she had offered in the first temple.
She now goes and dips all the remaining flowers into the third well and the flowers get doubled, again. She goes inside the third temple and offers the same number of flowers as many she had offered in the first temple. And she has now no flowers left with her, as she leaves the place.
How many flowers did she pluck and how many flowers did she offer in each temple?
Try solving it and send me your answer and solution if you want to.
I like this puzzle as an interview question because this being of reasonable length I get an opportunity to gauge the listening ability of the candidate. Their approach to the problem and their questions help me to know how good the analytical skills of the interviewee are. I could also increase the complexity of the puzzle if the candidate answers well.
The rest remaining the same, if the first well doubled the number of flowers, the second trebled them and the third well quadrupled them, then how many flowers did she pluck and how many flowers did she offer in each temple?
Finally, I convert it into a software programming problem by asking them to write a program to find the solution and then increase the complexity by asking them to solve the same if there were four or five or more pairs of temples and wells.
It’s quite interesting that a puzzle that I learned in school days, helps me to assess the candidates.