Many candidates were able to show that the nth term is 9n + 22 but they did not use this formula to calculate the 20th term. Rather, they used the general formula which was not required of them. They were expected to substitute 20 for n in the expression to get 9(20) + 22 = 202.
Candidates also performed well in the (b) part of the question. They were able to derive the equations ar = 1 and ar4 =1/8 .
However, some of them were not able to solve for a and r correctly because of the fraction involved and this also affected their getting the eighth term correctly.
Questions 14 and 15 were not meant for candidates in Nigeria and no responses were required.
