Three points `P, Q and R` are selected at random from the cirumference of a circle. Find the probability p that the point lie on a semi-circle

The length of a tangent from point A at distance 5cm from the center of the circle is 4cm. Find the radius of the circle.

The line integral or an electric field along the circumference of a circle of radius r, drawn with a point charge Q at the centre will be.........

Out of 3n consecutive integers, three are selected at random. Find the probability that their sum is divisible by 3.

A is a set containing n elements. A subset P of A is chosen at random and the set A is reconstructed by replacing the random. Find the probability that Pcup Q contains exactly r elements with 1 le r le n .

Find the probability that a number selected at random from 1 to 100 is a prime number.

Three particles P, Q and R are situated at point A on the circular path of radius 10m. All three particles move along different path and reach at point B shown in figure. Then the ratio of distance traversed by particle P and Q is:-

Three squares of chess board are selected at random. Find the probability of getting 2 squares of one colour and other of a different colour.

A person has 21 tickets with numbered 1 to 21. Three tickets are selected from it at random. Find the probability of an event that numbers of selected three tickets are in A.P.

A point P is at the 9 unit distance from the centre of a circle of radius 15 units. The total number of different chords of the circle passing through point P and have integral length is