Find the sum of the first terms of the arithmetic progression

Answer and explanation

Correct answer: B.

  1. Step 1: with , , . Step 2. . **Answer: . Why not the others:** is what you get if you forget to halve. is what you get if you use instead of . is what you get if you leave out the first term.

Practise more Geometry, trigonometry and probability.

Free questions with an explanation for every one, and full timed DTM University Entrance Test (Uzbekistan) mock tests.