The first term of an arithmetic progression is and its common difference is . What is the sum of its first terms?
Answer and explanation
Correct answer: C. 192
**
- Step 1: The sum of an arithmetic progression is determined by .
- Step 2: With , , and , we evaluate .
- Step 3: Simplifying the product gives .
Answer
192.
Why not the others: '408' evaluates the summation using terms instead of ; '200' omits the factor of in the series formula; '186' adds rather than subtracts the common difference term.
Practise more Sequences and series.
Free questions with an explanation for every one, and full timed JEE Main mock tests.
More Sequences and series questions
- The first term of an arithmetic progression is and its common difference is . What is the sum of its first terms?
- The first term of an arithmetic progression is and its common difference is . What is the sum of its first terms?
- The first term of an arithmetic progression is and its common difference is . What is the sum of its first terms?
- The first term of an arithmetic progression is and its common difference is . What is the sum of its first terms?
- The first term of an arithmetic progression is and its common difference is . What is the sum of its first terms?
- The first term of an arithmetic progression is and its common difference is . What is the sum of its first terms?