Question on Probability Quiz-1

Question 1

Time: 00:00:00

Marie is getting married tomorrow, at an outdoor ceremony in the desert. In recent years, it has rained only 5 days each year.

Unfortunately, the weatherman has predicted rain for tomorrow. When it actually rains, the weatherman correctly forecasts rain 90 of the time. When it doesn't rain, he incorrectly forecasts rain 10 of the time.

What is the probability that it will rain on the day of Marie's wedding?

0.567

0.111

0.332

0.732

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Question 2

Time: 00:00:00

Two squares are chosen at random on a chessboard. What is the probability that they have a side in common?

1/18

64/4032

63/64

1/9

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Question 3

Time: 00:00:00

In a game, there are 70 people of which 40 are boys and 30 are girls, out of which 10 people are selected at random. One from the total group, thus selected is selected as a leader at random. What is the probability that the person, chosen as the leader is a boy?

4/7

4/9

5/7

2/7

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Question 4

Time: 00:00:00

Four unit squares are chosen at random on a chessboard. What is the probability that three of them are of one color and fourth is of opposite color?

80/427

160/427

320/1281

640/1281

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Question 5

Time: 00:00:00

An eight-digit telephone number consists of exactly two zeroes. One of the digits is repeated thrice. Remaining three digits are all distinct. If the first three digits (from left to right) are 987, then find the probability of having only one 9, one 8 and one 7 in the telephone number.

1/18

1/20

1/10

5/47

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Question 6

Time: 00:00:00

Two urns contain 5 white and 7 black balls and 3 white and 9 black balls respectively. One ball is transferred to the second urn and then one ball is drawn from the second urn. Find the probability that the first ball transferred is black, given that the ball drawn is black?

13/23

11/23

14/23

7/23

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Question 7

Time: 00:00:00

McDonald's ran a campaign in which it gave game cards to its customers. These game cards made it possible for customers to win hamburgers, French fries, soft drinks, and other fast-food items, as well as cash prizes. Each card had 10 covered spots that could be uncovered by rubbing them with a coin. Beneath three of these spots were "No Prize" signs. Beneath the other seven spots were names of prizes, two of which were identical.

For example, one card might have two pictures of a hamburger, one picture of a Coke, one of the French fries, one of a milkshake, one of 5 Dollar, one of 1000 Dollar and three "No Prize" signs. For this card, the customer could win a hamburger.

To win on any card, the customers had to uncover the two matching spots (which showed the potential prize for that card) before uncovering a "No Prize"; any card with a "No Prize" uncovered was automatically void. Assuming that the two matches and the three "No Prize" signs were arranged randomly on the cards, what is the probability of a customer winning?

0.10

0.15

0.12

0.18

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Question 8

Time: 00:00:00

There are three similar boxes, containing
(i). 6 black and 4 white balls(ii). 3 black and 7 white balls(iii). 5 black and 5 white balls, respectively.
If you choose one of the three boxes at random and from that particular box picks up a ball at random, and find that to be black, what is the probability that the ball picked up from the second box?

14/30

3/14

7/30

7/14

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Question 9

Time: 00:00:00

Amit, Sumit, and Pramit go to a seaside town to spend a vacation there and on the first day, everybody decides to visit different tourist locations. After breakfast, each of the boards a different tourist vehicle from the nearest bus depot. After three hours, Sumit who had gone to a famous beach, calls on the mobile of Pramit and claims that he has observed a shark in the waters. Pramit learns from the local guide that at that time of the year, only eight sea-creatures (including a shark) are observable and the probability of observing any creature is equal. However, Amit and Pramit later recall during their discussion that Sumit has a reputation for not telling the truth five out of six times. What is the probability that Sumit actually observed a shark in the waters?

1/36

1/30

5/36

1/24

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Question 10

Time: 00:00:00

Dexter was born between October 6th and 10th10th (6th6th and 10th10th excluding). His year of birth is also known. What is the probability of Dexter being born on a Saturday?

0 or 3/7

1/7 or 3/7

1/3 or 1/7

Cannot be determined

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