Fungal herbicides are produced by which of the following?

Three numbers are chosen at random from $1$ to $20$. The probability that they are consecutive is

If $\int \frac{d x}{\sqrt{\sin ^3 x \cos x}}=g(x)+c$,then $g(x)$ is equal to

The minimum value of $2x^2+x-1$ is:

$A$ random variable $X$ takes the values $0, 1, 2, 3, \ldots$ with probability $P(X=x)=k(x+1)\left(\frac{1}{5}\right)^x$,where $k$ is a constant. Then $P(X=0)$ is

In $YDSE$ with two identical slits, when the upper slit is covered with a transparent sheet of mica, the second-order minima is observed above the center of the screen and the second-order maxima below it. Which of the following cannot be a possible value of the phase difference caused by the mica sheet?