I know its a long problem but i have to shiw how i got my answer.
The answer is B 36 because the chance of you grabbing a white or black is 12/15 meaning if you pulled 15 marbles, most likely 12 of them are white or black. so, because 15 goes into 45 3 times, you multiply 12/15 by 3 getting 36/ 45 meaning you will mostly pull 26 black or white marbles.
They both relatively easy depending on how much time you put into understanding but. But if I have to pick which is harder I’d say linear.
