211
Q:

A bag contains 4 white, 5 red and 6 blue balls. Three balls are drawn at random from the bag. The probability that all of them are red, is:

A) 2/91 B) 1/22
C) 3/22 D) 2/77

Answer:   A) 2/91



Explanation:

Let S be the sample space.

Then, n(S) = number of ways of drawing 3 balls out of 15 = 15C3  =15*14*133*2*1= 455.  

Let E = event of getting all the 3 red balls.

 n(E) = 5C3 = 5*42*1 = 10.

 => P(E) = n(E)/n(S) = 10/455 = 2/91.

Q:

If the standard deviation of 0, 1, 2, 3 ......... 9 is K, then the standard deviation of 10, 11, 12, 13 ........... 19 will be:

 

A) K+1 B) K
C) K+4 D) K+8
 
Answer & Explanation Answer: B) K

Explanation:
Report Error

View Answer Report Error Discuss

4 1202
Q:

The standard deviation of the set {10, 11, 12, 9, 8} is

A) 1 B) √2
C) 2 D) 2√2
 
Answer & Explanation Answer: B) √2

Explanation:
Report Error

View Answer Report Error Discuss

5 1198
Q:

Find the range of the data 2, 1, 2, 3, 5, 4, 7, 3, 5, 2, 4.

A) 5 B) 4
C) 3 D) 6
 
Answer & Explanation Answer: D) 6

Explanation:
Report Error

View Answer Report Error Discuss

2 1047
Q:

Find the median, mode and mean of 9, 5, 8, 9, 9, 7, 8, 9, 8.

A) 9, 9, 9 B) 9, 8, 9
C) 8, 9, 8 D) 8, 9, 9
 
Answer & Explanation Answer: C) 8, 9, 8

Explanation:
Report Error

View Answer Report Error Discuss

2 1061
Q:

In the usual set notation, A  (B  C) =

 

 

A) A∪B∪A∪C B) A∩B∪A∩C
C) A∪B∩A∪C D) A∪B∩A∩C
 
Answer & Explanation Answer: C) A∪B∩A∪C

Explanation:
Report Error

View Answer Report Error Discuss

2 4115
Q:

Find the range and mode of the data 17, 18, 28, 19, 16, 18, 17, 29, 18

A) 12 and 18 B) 13 and 18
C) 12 and 17 D) 11 and 17
 
Answer & Explanation Answer: B) 13 and 18

Explanation:
Report Error

View Answer Report Error Discuss

3 1252
Q:

Find the standard deviation of {11, 7, 10,13, 9}

A) 1 B) 2
C) 4 D) 5
 
Answer & Explanation Answer: B) 2

Explanation:
Report Error

View Answer Report Error Discuss

3 1347
Q:

A table tennis player, lost 12 games out of 18 games played. Calculate the games won in terms of decimal.

A) 0.667 B) 0.067
C) 0.50 D) 0.333
 
Answer & Explanation Answer: D) 0.333

Explanation:
Report Error

View Answer Report Error Discuss

3 1341