Dispersed non$-$coalescing droplets $($CA$0=5\mathrm{.}5$ mol$/$litre$)$ react

$($A $->$ R$,-$rA $=$ k CA$)$ as they pass through a contactor.

Find the average concentration of A remaining in the droplets leaving the contactor if their RTD is given by the curve in the figure below.

K$=0\mathrm{.}35$

Show all working step by step do not use python $,$ Thanks $!$