The value of k if (1,2), (k,-1) are conjugate points with respect to the ellipse 2x²+3y²=6 is

At a selection, the probability of selection of A is 1/7 and that of B is 1/5.The probability that both of them would not be selected is

The eccentricity of the ellipse 25x²+9y²-150x-90y+225=0 is

In a town 40% people red Enadu, 25% people read jyothi and 15% people read both. A person is chosen at random from the town. The probability that the person chosen read Enadu but not read jyothi is

6 boys and 4 girls sit around a round table at random. The probability that the no two girls sit together is

100 tickets are numbered as 00, 01, 02,...,09, 10, 11,...99. When a ticket is drawn at random from them and if A is the event of getting 9 as the sum of the numbers on the ticket, then P(A)=

A bag contains 5 red, 3 black balls and another bag contains 4 red and 5 black balls. One of the bags is chosen at random and a draw of two balls is made from it. The chance that one id red and the other is black is

A lot consists of 12 good pencils, 6 with minor defects and 2 with major defects. A pencil is drawn at random. The probability that this pencil is not defective is

Mr. A is called for 3 interviews .There are 5 candidates at the first interview, 4 at the second and 6 at the third .If the selection of each candidates is equally likely then the probability that A will be selected for at least  one post is

A bag contains2whit, 3 black and 4greenballs. If2 balls are drawn from it, one after another then the probability that the first one is white and the second one is black is