CBSE - Probability

1 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 

2 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 

3 Probability 

Mallica and Deepica are friends. Then the probability that both have same birthday is (ignoring aleap year)  
 
1) 364 / 365
2) 1 / 365
3) 363 / 365 
4) 2 / 365 

4 Probability 

Box A contains 30% first grade articles. Box B contains 40% first grade articles. One article is draw from each box. Then the probability that both articles drawn are first grade is   
 
1) 1 / 25
2) 3 / 25
3) 7 / 25 
4) 9 / 25 

5 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

6 Probability 

A bag contains 2 red, 3 green and 2 blue  balls. Two balls are drawn at random. What is the probability that none  of the balls drawn is blue? 
 
1)  10 / 21
2)  11 / 21
3)  2 / 7
4) 5 / 7 

7 Probability 

 Probability that a non leap year should have 53 Mondays, will be  
 
1) 2 / 7
2) 3 / 7
3) 1 / 7
4) 5 / 7

8 Probability 

A die is thrown twice. Then the probability that 5 will come up at least once is  
 
1) 11/ 36
2) 7 / 36
3) 5 / 36 
4) 0 

9 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

10 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