$1000l\frac{b}{h}er$ of a sold cortaining $0\mathrm{.}01l_b$ Nicotine per Ph of water is being exlracted by $1500l\frac{h}{m}$ of kerosin oil in a countir carrent exlaaclai containing & stages. Detuin the response of systems in a step change of $0\mathrm{.}015$ in the aquus feced concentration. When will be new ste ady stale stablished.

sop :

$y=0\mathrm{.}86x$

$Y=lb$ nicdine$/$les of kerwin oil

$x=$ Hroline $/$ hs of $H_{2}O$

Nicotime $=L,$ kersine oil $=C$

$E=\frac{y_n-y_{n-1}}{y_n^{**}-y_{n-1}}$