1/4 of a rod was painted red. 2/5 was painted orange and 2/7 of the remainder was painted yellow. The yellow section was 20cm long how long was the rod

Answer: 200cm longStep-by-step explanation:Let the length of the rod be xred = 1/4 of the rod , which means 1/4 of xorange = 2/5 of xThe remainder = x - ([tex]\frac{x}{4}[/tex] +[tex]\frac{2x}{5}[/tex])= x - ([tex]\frac{13x}{20}[/tex])= [tex]\frac{7x}{20}[/tex]yellow = 2/7 of the remainder , that is yellow = 2/7 of [tex]\frac{7x}{20}[/tex]yellow = [tex]\frac{x}{10}[/tex]and it was given that the yellow section was 20cm long , that is[tex]\frac{x}{10}[/tex] = 20cmx = 20 x10x = 200Therefore the rod was 200cm long