SPM Practice 1 (Arithmetic Progression) : Question 11

Question 11

An arithmetic progression consists of 10 terms. The sum of the last 5 terms is 5 and the fourth term is 9. Find the sum of this progression.

[ Hint : You can find the sum of the first five terms using

(a) Sn formula using S 5 : S n = n 2 [2a+(n1)d]
(b) Tn formula where S 5 = T 1 + T 2 + T 3 + T 4 + T 5]