The straight lines represented by the equation $9x^2 - 12xy + 4y^2 = 0$ are

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 :

Which of the following sulfates is insoluble in water?

The line joining the points $6a - 4b + 4c$ and $-4c$ and the line joining the points $-a - 2b - 3c$ and $a + 2b - 5c$ intersect at:

Pressure versus temperature graphs of an ideal gas are as shown in the figure. Choose the wrong statement.

Ethers,when dissolved in cold concentrated sulphuric acid,form: