What is the path difference for destructive interference?

The statement $(p$ $\rightarrow q)$ $\rightarrow [(\sim p$ $\rightarrow q)$ $\rightarrow q]$ is

Which of the following is the most stable alkene?

Let $n_e$ be the number density of electrons and $v_d$ be the drift velocity in a semiconductor. When the temperature is increased:

$(\sqrt{3}+i)^7+(\sqrt{3}-i)^7$ is equal to (in $\sqrt{3}$)

Out of $13$ cricket players,$4$ are bowlers. In how many ways can a cricket team of $11$ players be formed such that at least $2$ bowlers are included?