Nucellar polyembryony is reported in species of

The value of $k$ such that the lines $2x - 3y + k = 0$,$3x - 4y - 13 = 0$,and $8x - 11y - 33 = 0$ are concurrent,is

$A$ $20 \, cm$ length of a certain solution causes right-handed rotation of $38^\circ$. $A$ $30 \, cm$ length of another solution causes left-handed rotation of $24^\circ$. The optical rotation caused by a $30 \, cm$ length of a mixture of the above solutions in the volume ratio $1 : 2$ is:

The order and degree of the differential equation $\sqrt{\frac{dy}{dx}} - 4\frac{dy}{dx} - 7x = 0$ are

$A$ circular disc is rolling on a horizontal plane. Its total kinetic energy is $300\,J$. What is its translational kinetic energy in $J$?

In a $\triangle ABC$,the expression $\frac{(a+b+c)(b+c-a)(c+a-b)(a+b-c)}{4b^2c^2}$ is equal to: