Which of the following hydrides has the lowest boiling point?

If $a \neq p, b \neq q, c \neq r$ and $\left|\begin{array}{ccc}p & b & c \\ p+a & q+b & 2c \\ a & b & r\end{array}\right|=0$,then $\frac{p}{p-a}+\frac{q}{q-b}+\frac{r}{r-c}$ is equal to :

$A$ ball rolls without slipping. The radius of gyration of the ball about an axis passing through its center of mass is $K$. If the radius of the ball is $R$,what fraction of its total energy is associated with its rotational kinetic energy?

What is the product formed when phenol reacts with concentrated $HNO_3$?

How much protein does a $250 \ kg$ cow produce in a day (in $g$)?

Which of the following is a fossil plant?