Erry has a total of 23 marbles. the marbles are either blue or green. he has three more blue marbles than green marbles. how many blue marbles does he have

Bruce is getting materials for a chemistry experiment his teacher gives him a container that has 0.25 liter of liquid in it. bruce need to use 0.4 of this liquid for the experiment. how much liquid will bruce use?

How do i do this? i don’t understand

For f(x) = 3x+1 and g(x) = x2 - 6, find (g/f)(x)