In an arithmetic progression the sum of the first 8 terms is 148 and the sum of the next 8 terms is 404.
Using this information, answer the following:
(i) Translate the two given statements into a pair of simultaneous equations in the first term a and the common difference d.
(ii) Solve the equations found in part (i) to obtain the values of a and d.
(iii) With the values of a and d obtained, determine the sum of the first 20 terms of the progression.