Given geometric sequence: 1/2, 1/3, 2/9, 4/27
let the common ratio = r
[tex]r = \frac{1}{3} \div \frac{1}{2} =\frac{1}{3} \times \frac{2}{1} = \frac{2}{3} \\ [/tex]
Next number after 4/27 is:
[tex] \frac{4}{27} \times r = \frac{4}{27} \times \frac{2}{3} = \frac{8}{81} \\ [/tex]
[tex]next \: number \: is \: \boxed{ \frac{8}{81} }[/tex]