Arrange the following substrate in decreasing order of electrophilic addition reaction

If the area of an equilateral triangle inscribed in the circle $x^2+y^2+10x+12y+c=0$ is $27\sqrt{3}$ sq. units,then $c$ is equal to:

$A$ convex mirror of focal length $f$ forms an image which is $\frac{1}{n}$ times the object. The distance of the object from the mirror is

Two uniform strings $A$ and $B$ made of steel are made to vibrate under the same tension. If the first overtone of $A$ is equal to the second overtone of $B$ and if the radius of $A$ is twice that of $B$,the ratio of the lengths of the strings is :

During the depression of freezing point in a solution,which of the following are in equilibrium?