Case Study Chapter 14 Probability Mathematics

l. Read the following and answer Vasu’s mother bought 3 kg apples and 2 kg oranges from the market. Vasu counted them and found there were 15 apples and 12 oranges.

Question. Vasu kept remaining apples and oranges in two separate baskets. He found 13 apples were left out of which 2 were rotten. The probability of picking a good apple from the apple basket now, is   
(a) 1/15
(b) 1/13
(c) 11/13
(d) 2/11

Answer: C

Question. If probability of an event E is 0.75, then P(not E) is     
(a) 0.25
(b) 0.75
(c) 0
(d) 1

Answer: A

Question.The probability of an event can never be   
(a) zero
(b) less than zero
(c) one
(d) greater than zero and less than one

Answer: B

Question. Vasu’s brother picks one fruit from the bag. The probability that he picks an apple is    
(a) 1/27
(b) 1/15
(c) 1/2
(d) 5/9

Answer: D

Question. After his brother Vasu picks one fruit from the bag. The probability that he picks an orange is (given that his brother picked an apple).   
(a) 6/13
(b) 1/12
(c) 1/11
(d) 12/27

Answer: A

ll. Read the following and answer Two kids are playing with balls in a playing zone. They both are given basket full of balls.

Question. The probability that the ball drawn from the basket given is either red or blue, is     
(a) 2/9
(b) 5/9
(c) 1/3
(d) 2/3

Answer: B

Question. If the probability of getting a red ball from the basket containing 35 balls is 0.2, then number of red balls in the basket is     
(a) 2
(b) 5
(c) 7
(d) 10

Answer: C

Question. The probability of drawing a green ball from a bag is 3/11 . If there are 9 green balls in the bag, then the total number of balls in the bag is   
(a) 30
(b) 33
(c) 22
(d) 99

Answer: B

Question. If the basket contains 9 blue , 6 red and 12 yellow balls, then the probability of picking a yellow ball is     
(a) 1/12
(b) 12/27
(c) 1 /3
(d) 12/15 

Answer: B

Question. The probability that the ball drawn from the above basket is not blue is   
(a) 2/3
(b) 1/3
(c) 1/2
(d) 2 /9

Answer: A

lll. Read the following and answer Akriti and Sukriti have to start the game of ludo. They are fighting for who will start the game. They found two coins and decided to toss them simultaneously to know who will start the game.

Question. Sukriti says if I get atmost one tail, I will start the game. The probability that Sukriti will start the game is 
(a) 1/4
(b) 3/4 
(c) 1 /2
(d) 0 

Answer: B

Question. Which of the following cannot be the probability of an event?     
(a) 1/99
(b) 1.05
(c) 0.07
(d) 49/50

Answer: B

Question. How many possible outcomes are there?   
(a) 2
(b) 1
(c) 4
(d) 0

Answer: C

Question. The probability of success is 73%. Then the probability of failure is   
(a) 0.27
(b) 0.37
(c) 0.73
(d) 0.5

Answer: A

Question. Akriti says if I get atleast one head, I will win and start the game. The probability that Akriti will start the game is   
(a) 1 /2
(b) 1 /4
(c) 3/4  
(d) 1

Answer: C

lV. Read the following and answer A lot of garments consists of 30 round neck T-shirts out of which 12 are red and remaining are green and 25 V-neck T-shirts out of which 11 are red and remaining are green. Apoorv will buy either green round neck or red V-neck T-Shirt. Shekhar will buy only round neck T-shirt. Varun will buy only red colour T-shirt.

Question. The probability that the randomly selected T-shirt is acceptable to Varun is     
(a) 12/55
(b) 23/55
(c) 11/55
(d) 30/55

Answer: B

Question. The selected T-shirt was green round neck, so Apoorv accepted it. Another T-shirt was selected at random. The probability that it is again accepted by Apoorv is   
(a) 17/54
(b) 18/55
(c) 30/54  
(d) 14/27

Answer: D

Question. The probability that the randomly selected T-shirt is not acceptable to any of them is   
(a) 25/55
(b) 32/55
(c) 14 /55
(d) 18/55

Answer: C

Question. The total possible outcomes is     
(a) 30
(b) 25
(c) 55
(d) 78

Answer: C

Question. One T-shirt is selected at random from the lot. The probability that it is acceptable to Shekhar is     
(a) 6 /11
(b) 42/55
(c) 5 /13
(d) 23/55

Answer: A

V. Read the following and answer A teacher conducted a fun activity in the class. She put cards numbered from 9 to 90 in a box. Then she called students one by one, from the teams formed by her. The child speaks out any property related to numbers. If he gets a number satisfying that property, the team scored marks otherwise not. 

Question. Preeti says ‘a prime number’. The probability of her team getting marks is     
(a) 19/82
(b) 11/42
(c) 10/41
(d) 21/83

Answer: C

Question. Karan says ‘an odd number’. The probability of getting score in this case is   
(a) 20/41
(b) 1/2 
(c) 1/4
(d) 1/3

Answer: B

Question. Which of the following property will have maximum chances of getting marks ?     
(a) an even prime number
(b) an even number
(c) a one digit number
(d) a two-digit number

Answer: D

Question. Vanshika speaks out ‘divisible by 6’. The probability that her team gets mark is     
(a) 1/6
(b) 7/41 
(c) 7/45
(d) 5/27

Answer: B

Question. Sam speaks out ‘a perfect square number’. The probability of his team getting marks is   
(a) 7/82
(b) 8/82
(c) 10/82
(d) 7/90

Answer: B

Vl. Read the following and answer Aisha took a pack of 52 cards. She kept aside all the face cards and shuffled the remaining cards well.    

Question. The probability of drawing a black queen is     
(a) 1/26
(b) 1/6
(c) 0
(d) 1

Answer: C

Question. The number of favourable outcomes for the event a club card or a ‘4’ is     
(a) 13
(b) 17
(c) 14
(d) 12

Answer: A

Question. The number of total possible outcomes is     
(a) 52
(b) 40
(c) 36
(d) 48

Answer: B

Question. The probability of getting neither a black card nor an ace card is   
(a) 9/20 
(b) 11/20
(c) 3/5
(d) 7/13

Answer: A

Question. She drew a card from the well-shuffled pack of remaining cards. The probability that the card drawn is a red card is     
(a) 1/4 
(b) 1 /2
(c) 4 /13
(d) 2/13

Answer: B

Vll. Read the following and answer Two friends are travelling in a bus. They were feeling bored, so they started playing a game with a pair of dice that one of them had. Each of them started rolling the pair of dice one by one, stating one condition before rolling. If the person gets the numbers according to the condition stated by him, he wins and get a score

Question. First one says, “6 will not come up either time”. The probability of his losing is     
(a) 1/4
(b) 25 /36
(c)  11/36
(d) 1/6

Answer: C

Question. The number of possible outcomes on rolling a pair of dice is     
(a) 6
(b) 12
(c) 36
(d) 8

Answer: C

Question. First friend says, “a doublet”. The probability of his winning is     
(a) 5/6
(b) 1/6
(c) 5/18
(d) 1/2

Answer: B

Question. the Second friend says, ‘sum less than 9’. The probability of his winning is     
(a) 13/18
(b) 31/36
(c) 1/2
(d) 1/6

Answer: A

Question. Second one says, “sum is an even number”. The probability of his losing is     
(a) less than 1/2
(b) more than 1/2
(c) equal to 1/2
(d) 1

Answer: C