Probability Question 420
Question: A fair coin is tossed 100 times. The probability of getting tails an odd number of times is
Options:
A) $ \frac{1}{2} $
B) $ \frac{1}{8} $
C) $ \frac{3}{8} $
D) None of these
Correct Answer: A
Show Answer
Answer:
Solution:
The total number of cases are $ 2^{100} $ The number of favourable ways $ {}^{100}C_1+{}^{100}C_3+\,.......\,+{}^{100}C_{99}={2^{100-1}}=2^{99} $ Hence required probability $ =\frac{2^{99}}{2^{100}}=\frac{1}{2}. $
BETA
