It's not true.. probably the questions u have seen in which first guy or thing had a bigger share so to write them in a respective manner they would have written the bigger ratio first but as u'll solve more problems in future u'll find that there is no such pattern exists. u'll find ratios like 9:16 many times so I request u to solve more problems and urge u to not get carried away with whatever little things u see. If something is not given in the formulae section or theorem section then it's not a pattern .don't assume things. Take it light cheers!!