cA[t_,kI_,N_]:=Exp[-N*kI*t]

cI[t_,kI_,N_]:=N/(1-N)*(Exp[-N*kI*t]-Exp[-kI*t])

cP[t_,kI_,N_]:=1-cA[t,kI,N]-cI[t,kI,N]

Manipulate[Plot[{cA[t,kI,N],cI[t,kI,N],cP[t,kI,N]},{t,0,100},PlotRange->{0,1.1},AxesLabel->{"t/s","[X]/[A]_0"}],{kI,0.01,0.1},{N,0.1,10}]