In a geometric sequence, the $23$rd term is $16$ and the $24$th term is $24$. What is the $28$th term?
r = 24 / 16 = 3/2
28th term = 24 (3/2)^4 = 24 * (81 / 16) = (3/2) 81 = 243 / 2 = 121.5
+866 
