MATHEMATICS · Multi-part · A Level · Mathematics · Sequences and series · Sequences and series
Problem
In an arithmetic progression, the 5th term is 22 and the 15th term is 62.
(i) Find the first term and the common difference of the progression.
(ii) Calculate the 25th term.
(iii) Find the sum of the first 20 terms.
(iv) Verify that the 10th term found using your values of a and d lies between the 5th and 15th terms.