CBSE - Probability

1 Probability 

Out of a day’s production, which is 1000 machine  parts, 100 we re  found to be  sub-standard. The  probability that a part se le cte d at random be ing up to the  standard is
 
1) 1 / 10
2) 9 / 10
3) 2 / 10
4) 5 / 10

2 Probability 

There are 50 cards maked with the numbers 1 to 50. One card is drawn at random. What is the probability that number on the card is a prime number ?

1) 3 /10
2) 1 / 5
3) 1 / 4
4) 2 /15

3 Probability 

In a single throw of three dice, the probability of getting a total of 17 or 18 is 
 
1) 53/54
2) 51/54
3) 1/54 
4) 0 

4 Probability 

The probability of guessing the correct answer to a certain question is p/12. If the probability of not guessing the correct answer to the same question is 3/4, the value of p is  
 
1) 3
2) 4
3) 2
4) 1

5 Probability 

 A game consists of tossing a one rupee coin 3 times and noting its outcome each time. Hanif wins if all the tosses give the same result i.e., three heads or three tails, and loses otherwise. Calculate the probability that Hanif will lose the game.  
 
1) 1 / 4
2) 1
3) 3 / 4 
4) 0 

6 Probability 

Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5? 
1)  1 / 2
2)  2 / 5
3)  8/ 15
4) 9 / 20
 

7 Probability 

In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is: 
 
1) 21 / 46
2) 25 / 117
3) 1 / 50
4) 3 / 25 

8 Probability 

A die is thrown twice. The probability that 5 will not come up either of the time is :

(1) 35/36  
(2) 25/36 
(3) 1 / 36 
(4) 11/36

9 Probability 

Two cards are drawn together from a pack of 52 cards. The probability that one is  a spade and other is a heart, is :    
 
1) 3 / 20
2) 29 / 34
3) 47 / 100
4) 13 / 102 

10 Probability 

A die is thrown twice. The probability of the sum being odd, is
 
1) 1 / 2
2) 1 / 3
3) 1 / 4
4) 1 / 6