An arithmetic progression has first term and common difference . Find the sum of the first 30 terms.

Answer and explanation

Correct answer: A. 1185

  1. Step 1: . Step 2. . Answer: 1185. Why not the others: 2490: That multiplies the last term by instead of using the average of the first and last. 83: That is only the 30th term. 1188: That is off by one common difference.

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