the percentage of Americans having type B blood is 11%. If four Americans are chosen at random and independently, determine the probability that Exactly one of the four has blood type B

Answer 1

There are 4 ways you can choose the one who has type B

Chance that in a group of 4, 1 has type B = 0.11¹ (1 - 0.11)³

You need to calculate this then multiply by 4