A fair coin is tossed three times. Find the probability of getting two heads and one tail.
-
A.
(frac{1}{2}) -
B.
(frac{3}{8}) -
C.
(frac{1}{4}) -
D.
(frac{1}{8})
Correct Answer: Option B
Explanation
Pr(head) = (frac{1}{2}), Pr(tail) = (frac{1}{2}):Pr(2 heads)
= (frac{1}{2}) x (frac{1}{2}) = (frac{1}{4})
Pr(2 heads and tail) 3 times
= ((frac{1}{4}) x (frac{1}{2})) x 3
= (frac{3}{8})