In 2 bags, there are to be put together 5 red and 12 white balls, neither bag being empty. How must the balls be divided so as to give a person who draws 1 ball from either bag-\nOptions:\n(A) 9/18\n(B) 9/16\n(C) 9/11\n(D) 9/12\n(E) 9/13
Let’s work this out in a step by step way to be sure we have the right answer.
(B)
(1) Put 1 white in first bag, and all the remaining ball in second bag.

Probability = 12×0+12×51612×0+12×516 = 532532\n(2) To maximize, we put 1 red in the first bag, and all the remaining in the second.

Probability = 12×1+12×43212×1+12×432 = 9/16.

The final answer: (B)