How much more is the sum of the first (180) natural numbers than the sum of the first (179) natural numbers?
Answer and explanation
Correct answer: 180
The sum of the first 180 natural numbers contains all the terms in the sum of the first 179 natural numbers, plus only 180. Hence, \(S_{180}-S_{179}=180\). Option 16290 is the total sum \(1+2+\cdots+180\), not the difference between the two sums. Exam tip: The difference between consecutive partial sums is always the next term.
Frequently asked questions
What is the correct answer to this question?
180
Why is this the correct answer?
The sum of the first 180 natural numbers contains all the terms in the sum of the first 179 natural numbers, plus only 180. Hence, \(S_{180}-S_{179}=180\). Option 16290 is the total sum \(1+2+\cdots+180\), not the difference between the two sums. Exam tip: The difference between consecutive partial sums is always the next term.
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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