ANSWER
[tex] 36 \frac{2}{3} [/tex]
EXPLANATION
The nth term of the sequence is given by;
[tex] \frac{20}{3} + \frac{1}{3} (n + 1)[/tex]
To find the 89th term, we put n=89,
[tex] \frac{20}{3} + \frac{1}{3} (89+ 1)[/tex]
We simplify to obtain,
[tex] \frac{20}{3} + \frac{1}{3} (90)[/tex]
[tex] \frac{20}{3} + 30 = 36 \frac{2}{3} [/tex]
