Quantitative Aptitude • Ratio, Average & MixtureEasy
What is the average of the first 19 natural numbers?
A. 9.5
B. 19
C. 20
D. 10✓ Correct Answer
💡 Solution & Explanation
The sum of the first n natural numbers is n(n + 1)/2 = 19 × 20 ÷ 2 = 190. Average = 190 ÷ 19 = 10. For any evenly spaced list, the average is also the middle of the first and last numbers.
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