An arithmetic progression has its 8th term exceeding its 4th term by 20
MATHEMATICS · Subjective · A Level · Mathematics · Sequences and series · Sequences and series
Problem
An arithmetic progression has its 8th term exceeding its 4th term by 20, and its 12th term is 6 more than twice its first term.
(i) Form the two equations in the first term a and the common difference d that are implied by the given information.
(ii) Hence determine the values of a and d.
(iii) For this progression, find the term number whose value is 126.