In an arithmetic sequence the third term is 17 and the seventh term is 37. What is the 14th term?
Answer and explanation
Correct answer: D. 72
- Step 1: Seventh term - third term = 4d, so 4d = 37 - 17 = 20 and d = 5. Step 2. First term a = 17 - 2 x 5 = 7. Step 3. a_14 = 7 + 13 x 5 = 72. Answer: 72. Why not the others: 77: That is the next term, the 15th. 67: That is the previous term, the 13th. 28: That adds 1 for each step instead of the common difference.
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