Re: Number of 7yo children

Hi there,

Thank you very much for this question. I would be happy to share the solution to it:

• Since 7 years ago, there weren't 350m inhabitants in the US but less, you need to account for that population growth over these 7 years. You could, of course, alternatively calculate 350m ÷ (1 + 4%) and then divide that result by 75.

If you would like a more detailed discussion on how to best prepare for your upcoming interviews, please don't hesitate to contact me directly.

Best,

Hagen

Here's the thing. For simplification purposes, we tend to assume that there's equal distribution among age groups.

In reality… IT IS NOT TRUE. Usually we talk about the age pyramid, not the age cube, because in most countries (and in nature) the “base” of the pyramid tends to be larger.

The fact that the population is growing suggests that the base of the pyramid may be larger.

So it is easier and wiser to assume that the base includes it's “fair share” of people (equal distribution) + that 4% of population increase.

I see you already received a few useful answers, so I'll only confirm that the flat distribution is quite common when looking at ages. 

Of course, in practice, you don't have the same amount of people born across decades. 

Sharing with you an additional resource that you might find useful for casing, in particular around maths - a list of the most common terms that show up in interviews:

• Expert Guide: The Must-Know Consulting Terms for Interviews

Good luck!
Cristian

Hi there,

Just a few things to add:

• Good thinking on growth (it's a good thing to flag to interviewer!)
• Cases almost always have some form of “over” simplification
• Remember that you might need to consider/think about age splits in countries where there is absolutely a big difference (Japan, India, etc.)