A control system is represented by the block diagram shown in figure. ratio is C(s)R(s)
G1G3+G1G21+G3+H1+G1G3H2+G1G3H2
G1G3+G1G21+G3H1+G2+G1G3H2+G1G2H2
CR=PKΔKΔ
CR=G1G3+G1G21+G3+G2+G3H1+G1G3H2+G1G2H2