10. Casey, Bob, David are members of the same science team. Now they need to answer a true/false question. The three answer independently, with Casey and Bob each having an $80 \%$ probability of answering correctly, and David having a $50 \%$ probability of answering correctly. The team is considered to have answered correctly if two or three people answer correctly. What is the probability that the team answers correctly?
(A) $60 \%$
(B) $64 \%$
(C) $72 \%$
(D) $75 \%$
(E) $80 \%$
10.E.

Let $A=0.8$, then the probability that all three people answer correctly is $A \times$ $A \times 0.5=0.5 A^{2}$; the probability that Casey and Bob answer correctly while David answers incorrectly is $A \times A \times 0.5=0.5 A^{2}$; the probability that Casey and David answer correctly while Bob answers incorrectly is $A \times 0.5 \times(1-A)=$ $0.5 A(1-A)$; the probability that Bob and David answer correctly while Casey answers incorrectly is $A \times 0.5 \times(1-A)=0.5 A(1-A)$.
Therefore, the probability that the group is correct is
$$
0.5\left[\left(A^{2}+A^{2}+A(1-A)+A(1-A)\right]=A\right. \text {. }
$$