Question 261317
probability of a person being left handed is 10% = .1
probability of a person being right handed is 1 - .1 = .9


p(1 left and 1 right) = .1*.9 * 2 = .18


you multiply by 2 because it can happen in 2 ways.


first way is you pick the first person who is left handed and then you pick the second person who is right handed.


second way is you pick the first person who is right handed and then you pick the second person who is left handed.


total possibilities are 0 left and 2 right, 1 left and 1 right, 2 left and 0 right.


p(0 left and 2 right) = .9^2 = .81
p(1 left and 1 right) = .1 * .9 * 2 = .18
p(2 left and 0 right) = .1^2 = .01


total probability is .81 + .18 + .01 = 1 as it should.


your answer is .18.