The equation of the parabola with focus $(0, 0)$ and directrix $x + y = 4$ is

Consider the circle $x^2+y^2-4x-2y+c=0$ whose centre is $A(2,1)$. If the point $P(10,7)$ is such that the line segment $PA$ meets the circle at $Q$ with $PQ=5$,then $c$ is equal to

Two ions having masses in the ratio $1:1$ and charges in the ratio $1:2$ are projected into a uniform magnetic field perpendicular to the field with speeds in the ratio $2:3$. The ratio of the radii of the circular paths along which the two particles move is

Select the correct arrangement of neural organization,according to the increasing degree of complexity.

Three students $A, B$,and $C$ are given a mathematics problem. The probabilities of them solving the problem are $1/2, 1/3$,and $1/4$ respectively. What is the probability that the problem is solved?

In which of the following arrangements,the sequence is not strictly according to the property written against it?