  This paper is devoted to investigate the exact solutions of Bianchi type $I$
spacetime in the context of $f(R,T)$ gravity [1], where $f(R,T)$ is an
arbitrary function of Ricci scalar $R$ and trace of the energy momentum tensor
$T$. For this purpose, we find two exact solutions using the assumption of
constant deceleration parameter and variation law of Hubble parameter. The
obtained solutions correspond to two different models of the universe. The
physical behaviour of these models is also discussed.
