Blood types A, B, O, and AB have percentages 40%, 20%, 30% and 10%. If two individuals are chosen at random, assuming independence, how do you find probability that both blood type A?

1 Answer
Sep 11, 2016

Answer:

#0.16#.

Explanation:

Let, #A_1# be the Event that the randomly chosen First Individual has

the Blood Group #A#, and, let, #A_2# be for the Second Individual.

#:." The Reqd. Prob.="P(A_1nnA_2)#.

But, #A_1 and A_2# are Independent Events, therefore,

# P(A_1nnA_2)=P(A_1)*P(A_2).............................................(star)#.

Since, 40% of Individuals have Blood Group A, clearly,

#P(A_1)=P(A_2)=40/100=0.4#

Hence, by #(star), "the Reqd. Prob."=0.4xx0.4=0.16#.