Junior Trader Interview Questions

You can't answer since the a priori probabilities haven't been given. If red and black are equally likely, then 1/3 is correct.

1 white marble. In order to end up with all black marbles, you need an even number of white marbles in the bag at some point. (So you can remove them all in pairs and return black marbles). This means you need an odd number of white marbles outside the bag. You start with 0 white marbles outside the bag. However, the number of white marbles outside the bag will always be a multiple of 2. You only ever add 0 or 2 white marbles to the marbles outside the bag (1 b 1 w = return 1 w = 0 white marbles. Remove 2 w marbles return one b = + 2 white marbles outside the bag) Since it is impossible to ever have an odd number of white marbles outside the bag, it is impossible to ever have an even number of white marbles inside the bag. Thus, you can rule out the possibility of there being 13 white marbles outside the bag. Leaving only 1 possibility. That is 12 white marbles outside the bag and 1 on the inside. The last marble is always white

I agree with nollag_trd, but to put it more succinctly: White marbles are only ever removed in pairs (if a single white is drawn, it's put back). There are an odd number of white marbles in the bag. Hence, the last white marble will never be removed.

Overcompetitiveness

I'm a workaholic

would u kindly share some examples to illustrate the difficulty. happy new year

I was as honest as possible. They can appreciated this a lot by the sounds of things.

It is a young dynamic group which I would fit into easily

Probability 1/2.