What is the sum of natural numbers from (1) to (19)?
Answer and explanation
Correct answer: 190
The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). Here \(n=19\), so the sum is \(\frac{19\times20}{2}=190\). Hence, option C is correct. The value 180 may result from an incorrect multiplication of 19 and 20. Exam tip: In the formula, substitute the last natural number for \(n\).
Frequently asked questions
What is the correct answer to this question?
190
Why is this the correct answer?
The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). Here \(n=19\), so the sum is \(\frac{19\times20}{2}=190\). Hence, option C is correct. The value 180 may result from an incorrect multiplication of 19 and 20. Exam tip: In the formula, substitute the last natural number for \(n\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: Sum of first n natural numbers.
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