passwella.
Menu

UI Post-UTME Mathematics 2019 (Model questions) Question 3

Question 3

Progressions

The first and the fourth terms of AP are 11 and 32 respectively. Find the sum of the first nine terms

  1. A.531
  2. B.135
  3. C.351
  4. D.315
Show the answer and explanation

Answer: C (351)

Explanation

11 + 3d = 32 gives d = 7. S₉ = 9/2 × (22 + 8 × 7) = 9/2 × 78 = 351.