MATHEMATICS · Subjective · A Level · Mathematics · Sequences and series · Sequences and series
Problem
In an arithmetic progression, the sum of the first 20 terms is 610, while the sum of the first 40 terms is 1640.
(i) Form two equations in the first term a and common difference d using the given information.
(ii) Solve the equations to find a and d.
(iii) Calculate the 100th term of the progression.
(iv) Find the sum of the first 100 terms.