PLEASE HELP. WILL DO ANYTHING.

Answer:
Sara could list the factors of 18 and 30 then find the greatest value the lists have in common. The length of the longest equal-sized pieces she can cut from both boards, with no wood left over, is 4.8 inches. She will be able to cut 3.75 pieces from the 18-inch board and 2.08 pieces from the 30 inch board. She would have enough wood to cut 10-equal pieces for he club project.
Explination:
I've explained everything in the comments. :)