What is the sum of natural numbers from (50) to (150)?
Answer and explanation
Correct answer: 10100
There are
\(150-50+1=101\) terms from 50 to 150, including both endpoints. Their average is
\(\frac{50+150}{2}=100\). Hence, the sum is
\(101\times100=10100\). The option 10050 results from an error in counting the inclusive terms or finding the average. Exam tip: for an inclusive range from \(a\) to \(b\), use \(b-a+1\) for the number of terms.
Frequently asked questions
What is the correct answer to this question?
10100
Why is this the correct answer?
There are
\(150-50+1=101\) terms from 50 to 150, including both endpoints. Their average is
\(\frac{50+150}{2}=100\). Hence, the sum is
\(101\times100=10100\). The option 10050 results from an error in counting the inclusive terms or finding the average. Exam tip: for an inclusive range from \(a\) to \(b\), use \(b-a+1\) for the number of terms.
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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