One of the most interesting interview question I was given is to estimate the number of cats in Singapore.
I was given time to think it over, and write my answer down on a piece of paper.
There are no right or wrong answers. It is meant to test one's creativity skills (or "smoking" skills).
I remembered that Singapore has a population of 4.2 million.
For simplicity, I assumed that all Singaporeans lived in flats.
Each flat has an average of 15 floors.
For every 5 floors, I assumed there is a houehold that kept 1 cat (guesstimate)
So there are 15/5 = 3 cats per block.
(1) Adding a 0.5 cat for stray cats loitering in void decks, we get 3.5 cats per block of flats.
From observations, each floor has an average of 8 units.
And each unit has 4 people living.
So that would equate to 8 x 4 = 32 people living per level per block.
(2) Which equates to 32 x 15 = 480 people living per block.
And that means for every 480 people, there are 3.5 cats.
And since I remembered that Singapore has approximately 4.2 million people (at that time of my interview), the number of cats will proportionately be about
4,200,000 / 480 x 3.5 = 30,625 cats.
That's the estimated number of cats in Singapore!
Anyone else have a different approach?
About the Author: Shingo T did manage to pass this round of interview, but didn't make it past the 3rd round of test.