What is the sum of natural numbers from (75) to (125)?
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Answer and explanation
Correct answer: 5100
There are \(125-75+1=51\) terms from 75 to 125. Their average is \(\frac{75+125}{2}=100\). Therefore, the sum is \(51\times100=5100\). A value such as 5150 can result from an error in counting the terms or finding the average. Exam tip: Always add \(+1\) when counting terms in an inclusive range.
Frequently asked questions
What is the correct answer to this question?
5100
Why is this the correct answer?
There are \(125-75+1=51\) terms from 75 to 125. Their average is \(\frac{75+125}{2}=100\). Therefore, the sum is \(51\times100=5100\). A value such as 5150 can result from an error in counting the terms or finding the average. Exam tip: Always add \(+1\) when counting terms in an inclusive range.
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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