A person can kill a bird with probability 3/4. He tries 5 times. What is the probability that he may not kill the bird

$\frac{1}{1024}$

Probability to kill a bird $p = \frac{3}{4},p+ q = 1 $

$⇒ q= 1-p = 1- \frac{3}{4}= \frac{1}{4}$ and $n = 5 $.

Probability that he may not kill the bird,

$P(X=0) = {^5C}_0 \left(\frac{3}{4}\right)^0. \left(\frac{1}{4}\right)^{5-0} = \frac{1}{1024}.$