Question

Pete painted 4/8 of a rectangle green he painted 1/8 of the same rectangle blue Pete painted the rest of the rectangle red what fraction of the rectangle did Pete paint red

Answer 1

3/8 of the rectangle because 4/8-1/8=3/8

Answer 2

The whole rectangle should be seen as 8/8 (not 1 to make it easier)
4/8 +1/8 = 5/8
8/8-5/8 = 3/8
So, Pete painted 3/8 of the rectangle red