a maths question, page-19

Yes , management take a marble .

Anyone at the site, at the time of start of shift is required to be at that meeting. They are not informed beforehand, and all take a marble.

Therefore the marble number may change , and the ratio of black and white change accordingly. Was using the 30 marbles as an example.

The reason I can't resolve this question in my head is because of my workmates arguement that (statistically) the last 4 marbles should be white.