An arithmetic sequence has first term 4 and common difference 2. Find the sum of the first 15 terms.
Answer and explanation
Correct answer: B. 270
- Step 1: .
- Step 2: .
Answer
270.
Why not the others: 32: that is the last term. 540: the factor is missing.
Practise more Sequences.
Free questions with an explanation for every one, and full timed Leaving Cert Ireland mock tests.
More Sequences questions
- An arithmetic sequence has first term 4 and common difference 2. Find the sum of the first 29 terms.
- In an arithmetic sequence the first term is 6 and the 20th term is 82. Find the common difference.
- In an arithmetic sequence the first term is 3 and the 17th term is 35. Find the common difference.
- An arithmetic sequence has first term 8 and common difference 3. Find the sum of the first 14 terms.
- In an arithmetic sequence the first term is 5 and the 13th term is 41. Find the common difference.
- An arithmetic sequence has first term 1 and common difference 2. Find the sum of the first 22 terms.