Thank you for the help!
How can I estimate the amount of KM an elevator does a day in a 200 meters hight business building?


Hi! Try to be as pragmatic as possible.
1. Estimate average distance per usage --> assume the same probability for each level, hence 100 metres on average --> double the distance because the elevator needs to get back to the ground floor --> 200m per usage
2. Estimate number of usages per day --> here you need to consider number of elevators in the building and different times of the day (heavy usage in the morning and evening, medium usage mid day, very low usage at night)
3. Multiply 1 with 2 to get the total meters per day.
Cheers, Sidi

Hello!
This is the classical GMAT question, hence, I would practice leveraging GMAT.
GMAT unfortunately only gets better with practicing. Good news is that there are many ways of doing so!
There are free exams in the internet that you can use for practice (the one of LBS MBA page, Verits prep, as well as some free trials for courses such as the one of The Economist (https://gmat.economist.com/)
Hope it helps!
Cheers,
Clara








