25
Q:

An urn contains 4 white 6 black and 8 red balls . If 3 balls are drawn one by one without replacement, find the probability of getting all white balls.

 A) 5/204 B) 1/204 C) 13/204 D) None of these

Explanation:

Let A, B, C be the events of getting a white ball in first, second and third draw respectively, then

Required probability = $PA∩B∩C$

Now, P(A) = Probability of drawing a white ball in first draw = 4/18 = 2/9

When  a white ball is drawn in the first draw there are 17 balls left in the urn, out of which 3 are white

$∴PBA=317$

Since the ball drawn is not replaced, therefore after drawing a white ball in the second draw there are 16 balls left in the urn, out of which 2 are white.

Hence the required probability = $29×317×18=1204$

Subject: Probability
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

Explanation:

Filed Under: Probability
Exam Prep: Bank Exams

13 989
Q:

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

 A) 1 B) 2 C) 4 D) 5

Explanation:

Filed Under: Probability
Exam Prep: Bank Exams

3 739
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

Explanation:

Filed Under: Probability
Exam Prep: Bank Exams

3 732
Q:

A sequence , has odd number of terms. Then the median is

 A) axn2+1 B) axn2-1 C) axn-1 D) axn2

Explanation:

Filed Under: Probability
Exam Prep: Bank Exams

3 5950
Q:

The mean of a distribution is 15 and the standard deviation is 5. What is the value of the coefficient variation?

 A) 16.66% B) 66.66% C) 33.33% D) 100%

Explanation:

Filed Under: Probability
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5 832
Q:

If the standard deviation of a population is 3, what would be the population variance?

 A) 9 B) 6 C) 8 D) 15

Explanation:

Filed Under: Probability
Exam Prep: Bank Exams

4 6092
Q:

The variance of a set of data is 169. Then the standard deviation of the data is

 A) +-13 B) 13 C) 69 D) 84.5

Explanation:

Filed Under: Probability
Exam Prep: Bank Exams

3 4946
Q:

If the standard deviation of a population is 10, what would be the population variance?

 A) 100 B) 30 C) 5 D) 20