In[]:=
prob[i_,j_,k_,l_,Ta_,Tb_]:=Sum[Binomial[ip,i]*Ta^i*(1-Ta)^(ip-i)*Binomial[jp,j]*Ta^j*(1-Ta)^(jp-j)*Binomial[kp,k]*Tb^k*(1-Tb)^(kp-k)*Binomial[lp,l]*Tb^l*(1-Tb)^(lp-l),{ip,1,Infinity},{jp,1,Infinity},{kp,1,Infinity},{lp,1,Infinity}]prob[1,0,1,0,Ta,Tb]
Out[]=
(-1+Ta)(-1+Tb)
2
Ta
2
Tb