- There are 5 boys and 3 girls. A group of 3 members is to be made. Find the probability that either there are 2 boys and 1 girl or 2 girls and 1 boy?
45/5644/5449/6452/58None of theseOption A

2 boy and 1 girl, prob. = 5C2*3C1/8C3

2 girl and 1 boy, prob. = 5C1*3C2/8C3

Add both the cases. - A carton contains 8 black and 7 grey balls. 2 balls are drawn one by one without replacement. What is the probability that the balls are alternately of different colors?
7/108/159/1410/15None of theseOption B

When 1st is black, probability = 8/15 * 7/14

When 1st is grey, probability = 7/15 * 8/14

Add both cases. - A carton contains 10 electric lights from which 2 lights are defective. Two lights are chosen at random. What is the probability that one of them is defective?
11/4314/4516/4515/35None of theseOption C

Probability=2C1*8C1/10C2 - A bag contains 8 black and 7 grey balls. A ball is drawn out of it and put back in the bag. Then a ball is drawn again. What is the probability that both the balls are grey?
49/22548/12525/9555/235None of theseOption A
- A bag contains 8 black and 7 grey balls. 2 balls are drawn one by one without replacement. What is the probability that the balls are alternately of different colors?
3/1410/128/157/156/15Option C

When 1st is black, probability= 8/15 * 7/14

When 1st is grey, probability = 7/15 * 8/14

Add both cases. - A bag 5 ruby and 8 white balls.Two draws of three balls each are made.What is the probability that the balls were ruby in the first draw and white in the second draw ?
140/20449145/2044520550/150Cannot be determinedNone of theseOption A

5C3/13C3 *8C3/13C3 - The ratio of the number of womens to the number of mens is 5 : 2 in a class of 21 persons. A group of three students is to to be selected at random amongst them. What is the probability that the selected group of persons contain one mens and two womens?
51/26045/26640/5537/255None of theseOption B

n(S) =21C3 = 1330

n(E) =15C1 × 6C2 = 15 × 15 = 225

Probability = 225/1330 = 45/266 - A bag contains 4 weige, 8 beige and 6 blue balls. If two balls are drawn at random, find the probability of both the balls being beige?
15/15425/15228/25327/250None of theseOption C

n(S) =18C2 =153

n(E) = 28

P(E) = 28 /153 = 28/153 - In a shelf, there are 7 Computer, 6 Maths and 5 CA books. One book is picked up randomly. What is the probability that it is neither in Computer nor in CA ?
1/51/81/31/7None of theseOption C

Probability=6/18 - If two dices are thrown simultaneously, what is probability that sum of numbers appeared is less than 7?
5/127/129/1410/15None of theseOption A