In an exercise, (1+2+3+\cdots+46) is to be found. What is the correct value?
Answer and explanation
Correct answer: 1081
The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). Here \(n=46\), so \(\frac{46\times47}{2}=23\times47=1081\). Therefore, the correct answer is 1081. A value such as 1071 can result from an error in multiplication or halving. Exam tip: take the last number as \(n\) and apply the formula directly.
Frequently asked questions
What is the correct answer to this question?
1081
Why is this the correct answer?
The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). Here \(n=46\), so \(\frac{46\times47}{2}=23\times47=1081\). Therefore, the correct answer is 1081. A value such as 1071 can result from an error in multiplication or halving. Exam tip: take the last number as \(n\) and apply the formula 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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