Good afternoon, I was recently at an assessment center and was asked an estimation question. This was the first one I've ever done so was wondering how everybody else would go about solving the problem.
I had 10 seconds to look at the attached photo, and then I was asked to calculate the mass of the London eye, I had 10 minutes to provide an answer.
Would somebody be able to do the same question and explain the methods?
It's not about providing an exact answer, but about your approach to handling such problems:
http://www.caseinterview.com/estimation-question-tips
So estimate the height (let's say 100m, though in fact it is 135). Making the circumference 316m.
From it's shape, I'd say that the circumference and 2 poles totaling about 184 meters contribute most to the weight. So we have 500m..
I would estimate that about each meter, you'd need the weight equivalent of a reasonably big car for the construction, so I'd say 500m * 1500 kg = 750 tons.
For construction, an engine that has to be placed somewhere, and inner parts, I'd round this up to 1000-1250 ton.
Actual answer is 2100 ton, but I think this is well within reasonable estimation range.