An aircraft gun can take a maximum of three shots at an enemy plane moving away from it. The probabilities of hitting the plane at the first, second and third shot are 0.5,0.4,0.3 respectively. The probability that the gun hits the place is

Bag A contains 8 black and 5 white balls. Bag B contain 6 black and 7 white balls. A die is rolled. If 2 or 5 turns up, then choose bag A otherwise choosen B. If one ball is drawn from the selected bag, the probability that it is black is

Bag a contains 4white and 5 black balls. Bag b contains 5 white and 6 black balls. One bag is selected at random and a ball is drawn from it. The probability that it is white is

In a committee consisting of 25 members,  everyone is  proficient in Mathematics or Physics or both .Among them 19memers are proficient in mathematics and 16 are proficient in Physics. If a person is chosen at random from the commitee, the probability that he is proficient both in Mathematics and Physics is

A problem in EAMCET examination is given to three students A, B and C, whose chances of solving it are 1/2, 1/3, 1/4 respectively. The probability that the problem will be solved is

A bag containing 12 two rupee coins, 7 one rupee coins and 4 half rupee coins.If 3 coinsare selected at random, then the probability that the sum of 3 coins is maximum is

In a bag there are 6 red, 4 black balls. From it 2 balls (without replacement) are drawn. If the first drawn ball is known to be red, the probability for the second drawn ball is also red is

The odds against A solving a problem are 8 to 6 and the odds in favour of B solving the same problem are 14 to 10. Then the probability that the problem will be solved if both of them try the problem is

Three numbers are selected at random without replacement from the set of numbers {1,2,...,n}. The conditional probability that the third number lies between the first two, if the first number is known to be smaller than the second, is

A bag consists a white and b black balls. Two players A and B alternatively draw a ball from the bag, replacing the ball each time after the draw till one of them draws a white ball and wins the game. A begins the game. If the probability of A winning the game is three times that of B, then a:b=