Question

A bag contains 4 black marbles, 2 white marbles, and 7 red marbles. Ted will select a marble from the bag without looking. What is the probability that he will select a black or a white marble? A. 2/3 B. 6/13 C. 3/13 D. 8/169

Answer 1

Probability of a black or white = What you want / total probability

so

you want either black or white...there are 4 black...and 2 white.......and in total there are 4 + 2 + 7 = 13 marbles..so you have

probability = 6 / 13