In a jar of ten beads, seven are red and three are blue. a bead is drawn from the jar five times with replacement. what is the probability of seeing exactly 2 blue beads?

In a jar of ten beads; since 3 are blue; probability of picking a blue ball, B, = p (b) = 3/10. And P (of not picking a blue ball); p (b') = 7/10. Since it occurs with replacement, probabilities doesn't change Probaility of picking k blue balls from on n attempts is given by P_n (k) P_n (k) = (n, k) p^ (k) q^ (n - k) where p and q are b and b' respectively. P_5 (2) = (5, 2) (0.3) ^ (2) (0.7) ^ (5 - 2) P_5 (2) = 5C2 (0.3) ^ (2) (0.7) ^ (3) = 0.3087