Data & Numbers
TNPSC - Group 1 Paper 1 — Quantitative Aptitude
2-min read·10 key concepts·10 facts
AI-Powered Analysis
29
PYQs Analyzed
2019–2025
Years Covered
Paper 1
TNPSC - Group 1
This subtopic covers statistical measures, probability, number patterns, and LCM/HCF. It is crucial for TNPSC exams as it tests numerical reasoning and analytical skills.
Key Concepts
Mean
Average of a set of numbers.
Median
Middle value when numbers are arranged in order.
Mode
Most frequently occurring value.
Range
Difference between highest and lowest values.
Standard Deviation
Measure of data spread from the mean.
Variance
Square of standard deviation.
Probability
Likelihood of an event occurring.
LCM & HCF
Least common multiple and highest common factor of numbers.
Number Patterns
Identifying sequences and series.
Prime Numbers
Numbers divisible only by 1 and themselves.
Must-Know Facts
- 1Standard deviation of 3, variance is 9.
- 2Mean of 2-16 is 10.
- 3Prime factors of 6 are 2, 3.
- 4First 10 primes range from 2 to 29.
- 5Mean of two-digit numbers is 54.5.
- 6Leap year has 53 Sundays with probability 2/7.
- 7Number of 3-digit numbers divisible by 6 is 150.
- 8Log10 2 ≈ 0.3.
- 9LCM of a and b is a implies b divides a.
- 10HCF of 15 allows pairs like (15, 30), (15, 45), etc.
Exam Patterns
Calculation-based questions on mean, median, mode.
Probability questions with dice and cards.
LCM/HCF problems with algebraic expressions.
Number pattern recognition.
Questions on prime numbers and their properties.
Common Traps
Confusing standard deviation with variance.
Forgetting to arrange numbers for median.
Misapplying LCM/HCF formulas.
Incorrectly calculating probability of prime sums.
Overlooking the effect of adding constants on standard deviation.
Year Highlights
2024LCM and HCF questions tested with multiple numbers and prime factors.
2025Number pattern and missing value questions appeared.
2022LCM and HCF problems with polynomials and algebraic expressions.
Practice these PYQs
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