Q. A bag contains 3 red balls and 2 blue balls. If one ball is drawn at random, what is the probability that it is red?
A.
1/5
B.
2/5
C.
3/5
D.
4/5
Show solution
Solution
The total number of balls is 3 + 2 = 5. The probability of drawing a red ball is 3/5.
Correct Answer:
C
— 3/5
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Q. A box contains 10 balls, 4 of which are red and 6 are blue. If one ball is drawn at random, what is the probability that it is not blue?
A.
2/5
B.
3/5
C.
4/10
D.
1/5
Show solution
Solution
The probability of not drawing a blue ball = Number of red balls / Total balls = 4/10 = 2/5.
Correct Answer:
A
— 2/5
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Q. A box contains 10 balls, 4 of which are red and 6 are blue. If one ball is drawn, what is the probability that it is blue?
A.
2/5
B.
3/5
C.
4/10
D.
6/10
Show solution
Solution
The probability of drawing a blue ball is 6/10 = 3/5.
Correct Answer:
B
— 3/5
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Q. A box contains 10 balls, 4 of which are white and the rest are black. If one ball is drawn at random, what is the probability that it is not black?
A.
1/5
B.
2/5
C.
3/5
D.
4/5
Show solution
Solution
Total balls = 10. Non-black balls = 4 (white). Probability = 4/10 = 2/5.
Correct Answer:
D
— 4/5
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Q. A box contains 10 balls, 4 of which are white and the rest are black. If one ball is drawn at random, what is the probability that it is not white?
A.
2/5
B.
3/5
C.
4/5
D.
1/5
Show solution
Solution
The total number of balls is 10. The number of non-white balls is 10 - 4 = 6. Thus, the probability of drawing a non-white ball is 6/10 = 3/5.
Correct Answer:
B
— 3/5
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Q. A box contains 5 white and 3 black balls. If one ball is drawn at random, what is the probability that it is not black?
A.
3/8
B.
5/8
C.
1/2
D.
7/8
Show solution
Solution
The probability of not drawing a black ball is the probability of drawing a white ball, which is 5/8.
Correct Answer:
B
— 5/8
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Q. A box contains 5 white and 3 black balls. If two balls are drawn at random, what is the probability that both are white?
A.
1/28
B.
5/28
C.
15/28
D.
3/28
Show solution
Solution
The probability of drawing 2 white balls = (5/8) * (4/7) = 20/56 = 5/14.
Correct Answer:
B
— 5/28
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Q. A card is drawn from a standard deck of 52 cards. What is the probability that the card drawn is a heart?
A.
1/4
B.
1/13
C.
1/52
D.
3/13
Show solution
Solution
There are 13 hearts in a deck of 52 cards. The probability of drawing a heart is 13/52 = 1/4.
Correct Answer:
A
— 1/4
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Q. A card is drawn from a standard deck of 52 cards. What is the probability that the card drawn is a queen?
A.
1/13
B.
1/52
C.
1/26
D.
3/52
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Solution
There are 4 queens in a deck of 52 cards. Probability = 4/52 = 1/13.
Correct Answer:
A
— 1/13
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Q. A die is rolled. What is the probability of rolling an even number?
A.
1/2
B.
1/3
C.
1/6
D.
2/3
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Solution
The even numbers on a die are 2, 4, and 6, which gives us 3 favorable outcomes. The total outcomes are 6. Therefore, the probability is 3/6 = 1/2.
Correct Answer:
A
— 1/2
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Q. A family has 2 children. What is the probability that both children are boys if it is known that at least one is a boy?
A.
1/2
B.
1/3
C.
1/4
D.
1/5
Show solution
Solution
The possible combinations of children are BB, BG, GB, GG. Given that at least one is a boy, we can eliminate GG, leaving us with BB, BG, GB. Out of these 3 combinations, only 1 is BB. Therefore, the probability is 1/3.
Correct Answer:
B
— 1/3
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Q. A family has 2 children. What is the probability that both children are boys, given that at least one is a boy?
A.
1/3
B.
1/2
C.
1/4
D.
2/3
Show solution
Solution
The possible combinations are BB, BG, GB. Given at least one is a boy, the combinations are BB, BG, GB. The probability of both being boys is 1/3.
Correct Answer:
A
— 1/3
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Q. A family has 2 children. What is the probability that both children are boys?
A.
1/4
B.
1/2
C.
1/3
D.
1/5
Show solution
Solution
The possible combinations of children are BB, BG, GB, GG. Out of these, only 1 combination is both boys (BB). Thus, the probability is 1/4.
Correct Answer:
A
— 1/4
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Q. A jar contains 4 red, 5 green, and 6 blue marbles. If one marble is drawn at random, what is the probability that it is not green?
A.
1/3
B.
2/3
C.
1/2
D.
5/11
Show solution
Solution
Total marbles = 4 + 5 + 6 = 15. Non-green marbles = 4 + 6 = 10. Probability = 10/15 = 2/3.
Correct Answer:
B
— 2/3
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Q. A jar contains 4 red, 5 green, and 6 blue marbles. If one marble is drawn at random, what is the probability that it is not blue?
A.
1/3
B.
2/3
C.
1/2
D.
5/11
Show solution
Solution
Total marbles = 4 + 5 + 6 = 15. Non-blue marbles = 4 + 5 = 9. Probability = 9/15 = 3/5.
Correct Answer:
B
— 2/3
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Q. A jar contains 4 red, 5 green, and 6 blue marbles. If one marble is drawn at random, what is the probability that it is either red or green?
A.
4/15
B.
3/5
C.
9/15
D.
1/3
Show solution
Solution
Total marbles = 4 + 5 + 6 = 15. Probability of red or green = (4 + 5)/15 = 9/15 = 3/5.
Correct Answer:
B
— 3/5
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Q. A jar contains 4 red, 5 green, and 6 blue marbles. What is the probability of drawing a green marble?
A.
1/3
B.
5/15
C.
5/15
D.
1/5
Show solution
Solution
Total marbles = 4 + 5 + 6 = 15. Probability of green = 5/15 = 1/3.
Correct Answer:
A
— 1/3
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Q. A jar contains 4 red, 5 green, and 6 blue marbles. What is the probability of picking a green marble?
A.
5/15
B.
1/3
C.
1/5
D.
1/2
Show solution
Solution
The total number of marbles is 4 + 5 + 6 = 15. The probability of picking a green marble is 5/15 = 1/3.
Correct Answer:
B
— 1/3
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Q. A jar contains 4 red, 5 green, and 6 blue marbles. What is the probability of randomly selecting a green marble?
A.
1/3
B.
5/15
C.
5/15
D.
1/5
Show solution
Solution
The total number of marbles is 4 + 5 + 6 = 15. The probability of selecting a green marble is 5/15 = 1/3.
Correct Answer:
A
— 1/3
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Q. A jar contains 5 red, 3 green, and 2 blue marbles. If one marble is drawn at random, what is the probability that it is either red or green?
A.
1/2
B.
2/5
C.
4/5
D.
3/5
Show solution
Solution
Total marbles = 5 + 3 + 2 = 10. Favorable outcomes (red or green) = 5 + 3 = 8. Probability = 8/10 = 4/5.
Correct Answer:
C
— 4/5
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Q. A jar contains 5 red, 3 green, and 2 blue marbles. What is the probability of drawing a green marble?
A.
1/5
B.
1/4
C.
3/10
D.
1/2
Show solution
Solution
Total marbles = 5 + 3 + 2 = 10. Probability of green = 3/10.
Correct Answer:
C
— 3/10
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Q. A jar contains 5 red, 3 green, and 2 yellow marbles. If one marble is drawn at random, what is the probability that it is either red or green?
A.
1/2
B.
4/5
C.
2/5
D.
3/5
Show solution
Solution
The total number of marbles is 5 + 3 + 2 = 10. The number of favorable outcomes (red or green) is 5 + 3 = 8. Thus, the probability is 8/10 = 4/5.
Correct Answer:
B
— 4/5
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Q. A student has a 70% chance of passing an exam. What is the probability that the student fails the exam?
A.
0.3
B.
0.7
C.
0.5
D.
0.2
Show solution
Solution
The probability of failing the exam is 1 - 0.7 = 0.3.
Correct Answer:
A
— 0.3
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Q. If a card is drawn from a standard deck of 52 cards, what is the probability that it is a heart?
A.
1/4
B.
1/13
C.
1/2
D.
1/52
Show solution
Solution
There are 13 hearts in a deck of 52 cards. Therefore, the probability P(heart) = 13/52 = 1/4.
Correct Answer:
A
— 1/4
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Q. If a die is rolled, what is the probability of rolling a number greater than 4?
A.
1/6
B.
1/3
C.
1/2
D.
1/4
Show solution
Solution
The numbers greater than 4 on a die are 5 and 6. There are 2 favorable outcomes out of 6 total outcomes. Therefore, P(number > 4) = 2/6 = 1/3.
Correct Answer:
B
— 1/3
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Q. If a student guesses on a multiple-choice test with 4 options for each question, what is the probability of guessing the correct answer?
A.
1/4
B.
1/2
C.
1/3
D.
1/5
Show solution
Solution
Probability of guessing correctly = 1/4.
Correct Answer:
A
— 1/4
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Q. If a student guesses on a multiple-choice test with 4 options per question, what is the probability of guessing the correct answer?
A.
1/4
B.
1/2
C.
1/3
D.
1/5
Show solution
Solution
Probability of guessing correctly = 1/4.
Correct Answer:
A
— 1/4
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Q. If a student is selected at random from a group of 20 students, 12 of whom are boys, what is the probability that the student is a boy?
A.
3/5
B.
2/5
C.
1/2
D.
1/3
Show solution
Solution
Probability = Number of boys / Total students = 12/20 = 3/5.
Correct Answer:
A
— 3/5
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Q. If a student is selected at random from a group of 20 students, 12 of whom are boys, what is the probability that the student is a girl?
A.
1/5
B.
2/5
C.
3/5
D.
1/2
Show solution
Solution
Number of girls = 20 - 12 = 8. Probability = 8/20 = 2/5.
Correct Answer:
C
— 3/5
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Q. If a student is selected at random from a group of 20 students, 8 of whom are girls, what is the probability that the selected student is a boy?
A.
1/2
B.
3/5
C.
2/5
D.
1/5
Show solution
Solution
There are 20 - 8 = 12 boys in the group. The probability of selecting a boy is the number of boys divided by the total number of students, which is 12/20 = 3/5.
Correct Answer:
B
— 3/5
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Showing 1 to 30 of 50 (2 Pages)
Probability Basics MCQ & Objective Questions
Understanding the fundamentals of Probability Basics is crucial for students aiming to excel in their exams. This topic not only forms the backbone of many mathematical concepts but also plays a significant role in scoring well in objective questions. By practicing MCQs and important questions related to Probability Basics, students can enhance their exam preparation and boost their confidence.
What You Will Practise Here
Basic definitions and concepts of probability
Types of probability: theoretical, experimental, and subjective
Key formulas for calculating probabilities
Understanding events: independent, dependent, and mutually exclusive
Application of probability in real-life scenarios
Common probability distributions and their properties
Solving objective questions and practice questions for better clarity
Exam Relevance
Probability Basics is a significant topic in various examinations such as CBSE, State Boards, NEET, and JEE. Students can expect questions that test their understanding of basic concepts, calculations, and real-world applications. Common question patterns include multiple-choice questions that require students to apply formulas and concepts to solve problems efficiently.
Common Mistakes Students Make
Confusing independent and dependent events
Misapplying probability formulas in different contexts
Overlooking the importance of sample space in calculations
Failing to distinguish between theoretical and experimental probability
FAQs
Question: What are the basic concepts of probability I should know?Answer: Key concepts include definitions of probability, types of events, and basic probability formulas.
Question: How can I improve my score in Probability Basics MCQs?Answer: Regular practice of objective questions and understanding the underlying concepts will greatly enhance your performance.
Start solving Probability Basics MCQs today to test your understanding and prepare effectively for your exams. Remember, practice is the key to success!
