BCG London Interview Process

Hi everyone 

I plan to apply for the BCG London experience hire consultant position, and wanted to quickly check with you on your understanding for the interview process (mentioned below) 

Specifically what the online quantitative reasoning assessment ? How can we prepare for it. 

As someone with diagnosed ADHD does BCG provide any sort of accommodation during quantitative tests ?   

As per BCG's website the process involves 
1. Online quantitative reasoning assessment, 
2. 2 x first round virtual interviews 
3. 2 x in-person final round interviews