relax man. hahahaa.
anywyas so theres no sure way to structure the planing part cause wlel they always ask for somehting different. i you notice in the markscheme they only give marks for the stated question . so just follow the questoins
as for dilution , think about it this ways, if 1 solution is more concentrated the only possible reason is that it has less water or less diluted however the number of moles is the same . thus consider the eqn
moles= concentration x volume
if both soln have the same number of moles the only difference is the volumes thus you can equate the formulaes for the two soln.
concsoln1) x vol (soln 1) = conc (soln 2) x vol (soln 2)
thus you sub in the respective concentrations vol and concentration you want into the soln and youll get the volume needed .
hope this helps pm me if you need furthur explanatoins