Which of the following reagents reacts differently with $HCHO$,$CH_3CHO$,and $CH_3COCH_3$?

If $p$ and $q$ are distinct prime numbers and if the equation $x^2 - px + q = 0$ has positive integers as its roots,then the roots of the equation are

$\sum_{k=1}^{2n+1} (-1)^{k-1} k^2$ is equal to

What is the full form of $GNP$?

The length of the common chord of the two circles $x^2+y^2-4y=0$ and $x^2+y^2-8x-4y+11=0$ is

If the lines $2x - 3y = 5$ and $3x - 4y = 7$ are two diameters of a circle of radius $7$,then the equation of the circle is