GATE Electrical 2014 Set 1 | Question: 27

Question

A fair coin is tossed $n$ times. The probability that the difference between the number of heads and tails is $(n-3)$ is

• A. $2^{-n}$
• B. $0$
• C. $^{n}C_{n-3}2^{-n}$
• D. $2^{-n+3}$