probability examples - Wikitechy https://www.wikitechy.com/interview-questions/tag/probability-examples/ Interview Questions Mon, 06 Sep 2021 06:43:37 +0000 en-US hourly 1 https://wordpress.org/?v=6.9 https://www.wikitechy.com/interview-questions/wp-content/uploads/2025/10/cropped-wikitechy-icon-32x32.png probability examples - Wikitechy https://www.wikitechy.com/interview-questions/tag/probability-examples/ 32 32 If the probability that A will live 15 year is 7/8 and that B will live 15 year is 9/10, then what is the probability that both will live after 15 year ? https://www.wikitechy.com/interview-questions/probability/if-the-probability-that-a-will-live-15-year-is-7-8-and-that-b-will-live-15-year-is-9-10-then-what-is-the-probability-that-both-will-live-after-15-year/ https://www.wikitechy.com/interview-questions/probability/if-the-probability-that-a-will-live-15-year-is-7-8-and-that-b-will-live-15-year-is-9-10-then-what-is-the-probability-that-both-will-live-after-15-year/#respond Wed, 18 Aug 2021 02:01:31 +0000 https://www.wikitechy.com/interview-questions/?p=2047

If the probability that A will live 15 year is 7/8 and that B will live 15 year is 910, then what is the probability that both will live after 15 year ?

A. 1/20

B. 63/80

C. 1/5

D. None of these

Answer : B. 63/80

Explanation:

P(A) = 7/8, P(B) = 9/10
Required Probability = P(A) x P(B)
= (7/8) x (9/10)
= 63/80.

]]> https://www.wikitechy.com/interview-questions/probability/if-the-probability-that-a-will-live-15-year-is-7-8-and-that-b-will-live-15-year-is-9-10-then-what-is-the-probability-that-both-will-live-after-15-year/feed/ 0 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 ? https://www.wikitechy.com/interview-questions/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/ https://www.wikitechy.com/interview-questions/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/#respond Wed, 18 Aug 2021 01:48:27 +0000 https://www.wikitechy.com/interview-questions/?p=2032

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 ?

A. 1/2

B. 2/5

C. 8/12

D. 9/20

Answer : D. 9/20…

Explanation:

Here, S = {1, 2, 3, 4, 19, 20}.
Let E = event of getting a multiple of 3 or 5
= {3, 6 , 9, 12, 15, 18, 5, 10, 20}.
P(E) = n(E) / n(S)
= 9/20

]]> https://www.wikitechy.com/interview-questions/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/feed/ 0 In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green ? https://www.wikitechy.com/interview-questions/probability/in-a-box-there-are-8-red-7-blue-and-6-green-balls-one-ball-is-picked-up-randomly-what-is-the-probability-that-it-is-neither-red-nor-green/ https://www.wikitechy.com/interview-questions/probability/in-a-box-there-are-8-red-7-blue-and-6-green-balls-one-ball-is-picked-up-randomly-what-is-the-probability-that-it-is-neither-red-nor-green/#respond Wed, 18 Aug 2021 01:43:40 +0000 https://www.wikitechy.com/interview-questions/?p=2029

In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green ?

A. 1/3

B. 3/4

C. 7/19

D. 8/21

E. 9/21

Answer : A. 1/3

Explanation:

Total number of balls = (8 + 7 + 6) = 21.
Let E = event that the ball drawn is neither red nor green
= event that the ball drawn is blue.
n(E) = 7
P(E) = n(E)/n(S)
= 7/21
= 1/3

]]> https://www.wikitechy.com/interview-questions/probability/in-a-box-there-are-8-red-7-blue-and-6-green-balls-one-ball-is-picked-up-randomly-what-is-the-probability-that-it-is-neither-red-nor-green/feed/ 0 A bag contains 4 black, 5 yellow and 6 green balls. Three balls are drawn at random from the bag. What is the probability that all of them are yellow ? https://www.wikitechy.com/interview-questions/probability/a-bag-contains-4-black-5-yellow-and-6-green-balls-three-balls-are-drawn-at-random-from-the-bag-what-is-the-probability-that-all-of-them-are-yellow/ https://www.wikitechy.com/interview-questions/probability/a-bag-contains-4-black-5-yellow-and-6-green-balls-three-balls-are-drawn-at-random-from-the-bag-what-is-the-probability-that-all-of-them-are-yellow/#respond Wed, 18 Aug 2021 01:37:06 +0000 https://www.wikitechy.com/interview-questions/?p=2026

A bag contains 4 black, 5 yellow and 6 green balls. Three balls are drawn at random from the bag. What is the probability that all of them are yellow ?

A. 2/91

B. 1/81

C. 1/8

D. 2/81

Answer : A. 2/91

Explanation:

Total number of balls = 4 + 5 + 6 = 15
Let S be the sample space.
n(S) = Total number of ways of drawing 3 balls out of 15 = 15C3
Let E = Event of drawing 3 balls, all of them are yellow.
n(E) = Number of ways of drawing 3 balls, all of them are yellow = Number of ways of drawing 3 balls from the total 5 = 5C3 (∵ there are 5 yellow balls in the total balls)
P(E) = n(E)/n(S) = 2/91

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