How much Paint is required to Paint a Skyscrapper

Question

I had a question and that was required to estimate what is the paint required to Paint a Skyscrapper

What I did was to evaluate the room I am sitting in with my interviewer and said that I believe that this room that is 4m*2m of area 8m2 requires half a bucket.

Now I estimated that specific skyscrapper had 50 floors.

For the length or height of each floor, I estimated that I am 1.8m in height and the height is almost 2x so thats one part of my equation. So the height is 50*1.8*2=180m (Is this analogy right?)

For the width I am confused, I wanted to use d=s*t but the issue is that I don't know how to calculate time. If I were to start at point A in the building, how much time does it take me to circle back to A. How can I know that and I don't even know whether A is the mid point or the starting point.

The building in question is somewhat oval similar to The Gerkin in London and would it matter really is the building is spherical or oval or rectangular like a hotel?

Please do let me know what is the best way to approach it.

Answer 1

Hi,

Just to clarify, are we talking about to paint the internal or external part of a Skyscraper? Because I believe it makes a lot of difference :)

In case it's internal, you have to take away from your calculation the width of the ceiling / floor (or state that it is already excluded from the calculation). When you have the width of 1 floor and you know the dimension of the room you are in, you can calculate all the surfaces (4 walls + ceiling) and then make an estimate on how many rooms are there on the floor (e.g., 2 open spaces + 4 rooms like the one you are into). Knowing the whole dimensions of the skyscraper, you can define the dimensions of the other rooms and calculate all the surfaces to be painted. (basically the whole skyscraper section for the ceiling + 2x number of walls, because they have to be painted on both sides). Than multiply for the number of floors.

In case it's external it is much easier, but it seems too much easier in that case.

Answer 2

Hi,

I believe you are going too much into details. You should be able to stop at the right level of approximation without digging yourself.

Best