  In this paper we consider the TASEP with second class particles with the
initial order is such that $k$ first class particles are located to the left of
$N-k$ second class particles. Under this assumption of the initial state of
order, we find the probability that the first class particles are at
$x,x+1,\cdots, x+k-1$ and the first class particles are still located to the
left of all second class particles at later time $t$. Moreover, we obtain an
explicit formula of this probability for the step initial condition. This
probability generalizes a result for $k=1$ in Lee (arXiv:1705.10544).
