Pls help. Thanks

Question

Tom has 2/3 as many green apples as red apples at first. After giving away 20 green apples and 20 red apples, he had 4/7 as many green apples as red apples. What was the total number of green and red apples Tom had in the end?

Answer 1

(3g - 20) / (2r - 20) = 4 / 7

7(3g - 20) = 4(2r - 20)

7(3g - 20) = 4(3g - 20)

21g - 140 = 12g - 80

9g = 60

g = 6 2/3 ??