Which of the following metals is present in Vitamin $B_{12}$?

The point in the eye of mammals from which optic nerves and blood vessels leave the eyeball is:

$A$ six-faced unbiased die is thrown twice and the sum of the numbers appearing on the upper face is observed to be $7$. The probability that the number $3$ has appeared at least once is:

The temperature in $K$ at which $\Delta G = 0$ for a given reaction with $\Delta H = -20.5 \ kJ \ mol^{-1}$ and $\Delta S = -50.0 \ J \ K^{-1} \ mol^{-1}$ is:

Which of the following is not a polyamide?

$A$ man pushes a wall and fails to displace it. He does: