A hat contains a number of cards with 30% white on both sides, 50% black on one side and whit e on the other side, 20% black on both sides. The cards are mixed up, and a single card is drawn at random and placed on the table. Its upper side shows up black. The probability that its other side is also black is

An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both balls are black?

An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both drawn balls are black?

A bag contains n+1 coins. If is known that one of these coins shows heads on both sides, whereas the other coins are fair. One coin is selected at random and tossed. If the probability that toss results in heads is 7/12, then find the value of ndot

Once again you are given four cards. Each card has a number printed on one side and a letter on the other side. Which are the only two cards you need to turn over to check whether the following rule holds? "If a card has a consonant on one side, then it has an odd number on the other side."

A purse contains 2 six-sided dice. One is normal fair die, while the other has two 1's, two 3's and two 5's. A die is picked up and rolled. Because of some secret magnetic attraction of the unfair die, there is 75% chance of picking the unfair die and a 25% chance of picking a fair die. The die is rolled and shows up the face 3. The probability that a fair die was picked up is

Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that (i) both balls are red. (ii) first ball is black and second is red. (iii) one of them is black and other is red.

Number 1, 2, 3, ...100 are written down on each of the cards A, B, and C. One number is selected at random from each of the cards. Then find the probability that the numbers so selected can be the measures (in cm) of three sides of right-angled triangles, no two of which are similar.

A cube having all of its sides painted is cut to be two horizontal , two vertical and other two planes, so as to form 27 cubes all having the same dimesions of these cubes, a cube is selected at random. If P_1 be the probability that the cube selected having atleast one of its sides painted, then the value of 27P_1 , is

State whether the following statements are true or false? Also give reasons for your answers. a) Only one line can pass through a given point. b) All right angles are equal. c) Circles with same radii are equal. d) A line segment can be extended on its both sides endlessly to get a straight line. e) From the figure, AB gt AC .