How many bacteria are produced in four hours if a bacterium divides once in half an hour?

The function $f(x) = |x| + \frac{|x|}{x}$ is

The lines $x-y-2=0$,$x+y-4=0$ and $x+3y=6$ meet at a common point:

An ovule which becomes curved so that the nucellus and embryo sac lie at right angles to the funicle is:

$A$ ray of light is incident on the surface of a glass plate at an angle of incidence equal to Brewster's angle $\phi$. If $\mu$ represents the refractive index of glass with respect to air,then the angle between the reflected and refracted rays is:

Which stage is indicated by the given figure?