Task: Question Answering
Input (English): Problem: a bag consists of 20 marbles, of which 5 are blue, 7 are red, and the remainder are white. if lisa is to select a marble from the bag at random, what is the probability that the marble will be red or white ?
Options: a. 3 / 4, b. 2 / 4, c. 1 / 4, d. 1 / 8, e. 1 / 16
Output (English): a