A, B, C are three routes from the house to the office. On any day, the route selected by the officer is independent of the climate. On a rainy day, the probabilities of reaching the office late, through these routes are 1/25, 1/10, 1/4respectively. If a rainy day the officer is late to the office then the probability that the route to be B is

If three six faced dice are thrown together, then the probability that the sum of the numbers appearing on the dice is k(3≤k≤8)is

If n positive integers are taken at random and multiplied together , the probability that the last digit of the product is 2,4,6 or 8 is

Five digit numbers can be formed from the digits 1,2,3,4,5. If one number is selected at random, the probability that it is an even number is

A bag contains four balls. Two balls are drawn and found them to be white. The probability that all the balls are white is

If 3 cards are drawn from a pack of cards, then the probability for the cards to be a king, a queen and a jack is

If the probability that A and B will die with in a year are p and q respectively, then the probability that only one of them will be alive at the end of the year is

The eccentricity o the ellipse 9x²+16y²=576 is

A bag contain 6 white and 4 black balls. A fair die is rolled and a number of balls equal to that appearing on the die is chosen from the bag at random. The probability that all the balls selected are white is

The vertex and focus of a parabola are (2, 1), (1, -1). Then the equation of the tangent at the vertex is