An arithmetic progression (AP) has first term 7 and common difference 3
MATHEMATICS · Subjective · A Level · Mathematics · Sequences and series · Sequences and series
Problem
An arithmetic progression (AP) has first term 7 and common difference 3. A geometric progression (GP) has the same first term 7 and common ratio 2. For the same number of terms n = 8, answer the following:
(i) Find the sum of the first 8 terms of the AP.
(ii) Find the sum of the first 8 terms of the GP.
(iii) Calculate the difference between the two sums, SGP−SAP.
(iv) State which of the two sums is larger and justify your answer on the basis of the numerical values obtained.