Can someone please help me solve this? I dont really understand this. The book is: PRINCIPLES AND MODERN APPLICATIONS OF MASS TRANSFER OPERATIONS $2$nd Edition by Jaime Benitez.

Design a sieve tray column for the absorber that is in Example $4\mathrm{.}4$ in the book. The foaming factor may be assumed as $0\mathrm{.}80$ in this problem. The liquid surface tension is that of water, $70dyn\frac{e}{c}m.$ Assume that the office diameter is on an equilateral triangular pitch with $20mm$ between centers of the orifices, with each orifice $3mm$ in diameter. The thickness of the tray can be assumed as $1mm$ thick. Design for a $60\%$ approach to the flood velocity.

a$)$ For this problem, design and report the parameters diameter of the tray, tray spacing, At$,$

$Ad,Aa,Lw,rw,$ and $Ah.$

b$)$ What are the advantages of using this approach instead of a $90\%$ approach?

c$)$ Estimate the tray gas pressure drop.