Statistics and Probability — Important Questions
Tamil Nadu Board · Class 10 · Mathematics
44 important questions from Statistics and Probability for Tamil Nadu Board Class 10 Mathematics, with answers. Includes multiple choice questions.
Interactive on Super Tutor
Studying Statistics and Probability? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for important questions and more.
Free trial, no card needed.
Learn better with visuals Super Tutor pairs illustrations like this with notes and quizzes for Statistics and Probability.
Important Questions from Statistics and Probability
If P(A) = 0.37, P(B) = 0.42, and P(A∩B) = 0.09, what is P(A∪B)?
Show answer
0.70
Step 1: Use the Addition Theorem: P(A∪B) = P(A) + P(B) - P(A∩B). Step 2: Substitute values: P(A∪B) = 0.37 + 0.42 - 0.09. Step 3: P(A∪B) = 0.79 - 0.09 = 0.70. Step 4: Common mistake is adding all three values (getting 0.88) instead of subtracting P(A∩B), or forgetting to subtract the intersection.
The standard deviation of data 7, 4, 8, 10, 11 is approximately 2.28. If each value is multiplied by 4, what is the new standard deviation?
Show answer
9.12
Step 1: Original σ ≈ 2.28 for data 4, 7, 8, 10, 11. Step 2: Key property: When all data values are multiplied by a constant k, the new standard deviation = k × original σ. Step 3: New σ = 4 × 2.28 = 9.12. Step 4: This is because multiplying each value by k scales the deviations from the mean by k, and hence σ scales by k. Common mistake: thinking σ stays the same (that's only for addition/subtraction of a constant).
In a class of 50 students, 28 opted for NCC, 30 opted for NSS, and 18 opted for both. What is the probability that a randomly selected student opted for NCC but NOT NSS?
Show answer
1/5
Step 1: n(S)=50, n(A)=28 (NCC), n(B)=30 (NSS), n(A∩B)=18. Step 2: P(A) = 28/50, P(A∩B) = 18/50. Step 3: P(NCC but not NSS) = P(A∩B̄) = P(A) - P(A∩B) = 28/50 - 18/50 = 10/50 = 1/5. Step 4: Common mistake is using 28 - 30 = incorrect subtraction, or forgetting to divide by n(S).
The variance of first n natural numbers is given by (n²-1)/12. For n=5, what is the standard deviation of the first 5 natural numbers?
Show answer
√2
Step 1: For n=5, variance σ² = (n²-1)/12 = (25-1)/12 = 24/12 = 2. Step 2: Standard deviation σ = √(variance) = √2. Step 3: Verify: Data = 1,2,3,4,5; mean = 3; Σ(xi-x̄)² = 4+1+0+1+4 = 10; σ² = 10/5 = 2; σ = √2 ✓. Step 4: Common mistake is computing variance as n²/12 without subtracting 1.
+40 more questions on Statistics and Probability (Tamil Nadu Board Class 10 Mathematics)
Practise AllFrequently Asked Questions
What are the important topics in Statistics and Probability for Tamil Nadu Board Class 10 Mathematics?
How many important questions are there in Statistics and Probability?
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Statistics and Probability
For serious students
Get the full Statistics and Probability chapter — start free.
Quizzes, flashcards, an AI doubt solver and a study plan for Tamil Nadu Board Class 10 Mathematics. Free to start, no card needed.