What will be the value of (1+2+3+\cdots+33)?
Answer and explanation
Correct answer: 561
The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). Here, \(n=33\), so \(\frac{33\times34}{2}=33\times17=561\). Option 544 can result from incorrectly using 32 instead of 33, but the sum runs from 1 to 33. Exam tip: take the last number as \(n\) and apply \(\frac{n(n+1)}{2}\) directly.
Frequently asked questions
What is the correct answer to this question?
561
Why is this the correct answer?
The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). Here, \(n=33\), so \(\frac{33\times34}{2}=33\times17=561\). Option 544 can result from incorrectly using 32 instead of 33, but the sum runs from 1 to 33. Exam tip: take the last number as \(n\) and apply \(\frac{n(n+1)}{2}\) directly.
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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