TT GWD9-23

dabiaoxun

Q23:

When tossed, a certain coin has equal probability of landing on either side.  If the coin is tossed 3 times, what is the probability that it will land on the same side each time?

 A. 1/8

B. 1/4

C. 1/3

D.3/8

E.1/2

Why the answer is B, not A?

Because both sides, 1/2*1/2*1/2*2, can sb. explain it to me?

Thanks

assurance

because there is either all tail or all face. If all face that is 1/2*1/2*1/2+(tail)1/2*1/2*1/2=1/4

robert

assurance回答的正确。应该是加法原理。