Which one of the following characters is not typical of the class Mammalia?

The variance of $50$ observations is $7$. If each observation is multiplied by $6$ and then $5$ is subtracted from it,then the variance of the new data is

$A$ force $F = -K(y\hat{i} + x\hat{j})$ (where $K$ is a positive constant) acts on a particle moving in the $xy$-plane. Starting from the origin,the particle is taken along the positive $x$-axis to the point $(a, 0)$ and then parallel to the $y$-axis to the point $(a, a)$. The total work done by the force $F$ on the particle is:

If the line $2x + 5y = 12$ intersects the ellipse $4x^2 + 5y^2 = 20$ in two distinct points $A$ and $B$,then the mid-point of $AB$ is

Which one of the following aqueous solutions will exhibit the highest boiling point?

Which of the following compounds has the highest boiling point?