By what is P i assume you mean what is the probability. Well probability is always the specific group divided by the total To find the total add all the marbles together 4 + 6 + 14 + 5 +8 = 37 Before we move on notice the question says that the marble is replaced after being chosen meaning the total stays the same for every pick Red Marbles Probability: red marbles/ total 6/37 or if you divide it out 0.162 Blue Marbles Probability: blue marbles/total 8/37 or 0.216