  We study the collective behavior of binary mixture of self-propelled
particles. Particles moves along their heading direction with {\it variable
speed} and interact through short range alignment interaction. A variable speed
parameter $\gamma >0$ is introduced such that for $\gamma=0.0$ model reduces to
{\it constant speed} Vicsek's model. We mix the particles with two different
$\gamma$'s and study the steady state behavior of the mixture for different
choice of $\gamma$'s and noise strength. One of the $\gamma$ is kept fixed to
$1.0$ and another one is varied from small $0.0$ to larger values $8.0$.
Properties of system is characterise by two types of order parameters (i)
orientation order parameter, which is a measure of ordering in the system and
(ii) density order parameter, which measures the phase separation is the
system. For all set of $\gamma$'s, system shows a transition from
disorder-to-ordered state on the variation of noise strength. The nature of
transition and critical noise is independent of value of $\gamma$, which is
also supported from coarse-grained hydrodynamic study. On the variation of
system parameters, ($\gamma$'s, $\eta$), we find four distinct phases, (i)
ordered phase separated, (ii) ordered mixed, (iii) disordered mixed and (iv)
disordered phase segragated. Our study shade light on different phases of
mixture of different types of active particles.
