An arithmetic progression has first term and common difference . Find the sum of the first 25 terms.

Answer and explanation

Correct answer: A. 1550

  1. Step 1: . Step 2. . Answer: 1550. Why not the others: 3050: That multiplies the last term by instead of using the average of the first and last. 122: That is only the 25th term. 1555: That is off by one common difference.

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