The apples are in a ratio of 4 red to 1 green.
If we add 4 to 1, we get 5.
The apples are in a ratio of 4 red to 5 apples.
Let the total number of red apples bought be x
4/5 = x/50
5x = 4 * 50
x = 4 * 10
x = 40
40 apples are red.
50 - 40 = 10
10 apples are red.
50 - 10 = 40
She has 40 more red than green apples.