Answer :
steve has x+500 marbles
richard has x marbles
if steve gives richard 300 marbles then
x+500-300 x+300
so x+200 and x+300
richard has more and by 100
richard has x marbles
if steve gives richard 300 marbles then
x+500-300 x+300
so x+200 and x+300
richard has more and by 100
Well Richard definetly has more now. Even is he started off with 0, he gains 300, and Steve only has 200 now, i dont think you can find out how many more, you'd need how much Richard started out with, or at least the total number of marbles. Hope that helped!! :-D