DSQ: Calculating discrete probability Practice Test

Data sufficiency question- do not actually solve the question

A bag of marbles consist of a mixture of black and red marbles. What is the probability of choosing a red marble followed by a black marble?

1. The probability of choosing a black marble first is $\frac{1}{3}$.

2. There are 10 black marbles in the bag.

One hundred marbles, 75 red and 25 white, are distributed equally between two boxes, denoted Box 1 and Box 2. Box 1 contains 30 red marbles.

One box is chosen at random, and one marble is chosen at random from that box. What is the probability that the marble chosen will be white?