The ninth term of an arithmetic series is 3
The sum of the first \(n\) terms of the series is \(S _ { n }\) and \(S _ { 21 } = 42\)
Find the first term and common difference of the series. [0pt]
[4 marks]
6
A second arithmetic series has first term - 18 and common difference \(\frac { 3 } { 4 }\)
The sum of the first \(n\) terms of this series is \(T _ { n }\)
Find the value of \(n\) such that \(T _ { n } = S _ { n }\) [0pt]
[3 marks]