Probability

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Q1. In a lottery, there are 10 tickets, and 2 are winning tickets. What is the probability of picking a winning ticket?

Solution:

Probability = Number of winning tickets / Total tickets = 2/10 = 1/5.

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Q2. A jar contains 8 red, 6 blue, and 4 green marbles. What is the probability of selecting a blue marble?

Solution:

Total marbles = 8 + 6 + 4 = 18. Probability of blue marble = 6/18 = 1/3.

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Q3. A box contains 4 white and 6 black balls. What is the probability of picking a black ball?

Solution:

Total balls = 4 + 6 = 10. Probability of black ball = 6/10 = 3/5.

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Q4. If a student guesses on a multiple-choice test with 4 options per question, what is the probability of guessing one question correctly? (2023)

Solution:

There is 1 correct answer out of 4 options, so the probability is 1/4.

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Q5. If a coin is tossed twice, what is the probability of getting at least one head?

Solution:

Total outcomes = 4 (HH, HT, TH, TT). Outcomes with at least one head = 3. Probability = 3/4.

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Q6. A box contains 4 white and 6 black balls. What is the probability of drawing a black ball? (2023)

Solution:

Total balls = 4 + 6 = 10. Probability of black ball = 6/10 = 3/5.

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Q7. In a group of 50 people, 20 are smokers. What is the probability that a randomly selected person is a non-smoker? (2021)

Solution:

There are 50 - 20 = 30 non-smokers. The probability is 30/50 = 3/5.

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Q8. A jar contains 10 candies, 4 of which are chocolate. What is the probability of selecting a chocolate candy?

Solution:

Probability of chocolate candy = 4/10 = 2/5.

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Q9. A jar contains 7 red, 5 blue, and 8 green marbles. What is the probability of selecting a blue marble?

Solution:

Total marbles = 7 + 5 + 8 = 20. Probability of blue marble = 5/20 = 1/4.

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Q10. In a game, the probability of winning is 0.2. What is the probability of losing? (2019)

Solution:

The probability of losing is 1 - 0.2 = 0.8.