  A Five dimensional Kaluza-Klein space-time is considered in the presence of a
perfect fluid source with variable G and $\Lambda$. An expanding universe is
found by using a relation between the metric potential and an equation of
state. The gravitational constant is found to decrease with time as $G \sim
t^{-(1-\omega)}$ whereas the variation for the cosmological constant follows as
$\Lambda \sim t^{-2}$, $\Lambda \sim (\dot R/R)^2$ and $\Lambda \sim \ddot R/R$
where $\omega$ is the equation of state parameter and $R$ is the scale factor.
