The first term of an arithmetic sequence is 3 and the common difference is 2. What is the 20th term?
Answer and explanation
Correct answer: C. 41
- Step 1: a_n = a_1 + (n - 1)d.
- Step 2: a_20 = 3 + 19 x 2 = 41.
Answer
41.
Why not the others: 43 uses n instead of n - 1; 39 uses n - 2; the second value treats the sequence as geometric.
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