how to write specific constraints?

[soNasty]

hello everyone im sure you all are confident for the further maths exam later today
however one thing always seems to get me whenever i do an exam, and it involves writing specific constraints.
im talking about the ones that are like "she always makes sure she spends at least three times as many hours studying further mathematics than studying chemistry (x=further, y=chem)
how would i go about in approaching these questions? its annoying sometimes because i always seem to get the answer but in the reverse order, like for the abovementioned question i'd put y>3x (greater than or equal to i mean)
rather than the actual answer of x>3y

so can someone please try and explain to me the best way to undertake these sort of questions? all im hoping is that theyre not on the exam today or monday.

[plato]

See  Linear Graphs Question

[soNasty]

thank you i get it now.