Boron in green plants assists in

The structure of $H_2O_2$ is

The number of proper subsets of the set ${1, 2, 3}$ is

An object with a mass $10 \ kg$ moves at a constant velocity of $10 \ m/s$. $A$ constant force then acts for $4 \ s$ on the object and gives it a speed of $2 \ m/s$ in the opposite direction. The impulse acting on the object is (in $N \cdot s$):

If $5x - 12y + 10 = 0$ and $12y - 5x + 16 = 0$ are two tangents to a circle,then the radius of the circle is

The eccentricity of the ellipse $9x^2 + 5y^2 - 18x - 20y - 16 = 0$ is: