1. For the backward problem, there was no wine after the third meeting with the garden, one barrel before the third meeting with the restaurant, 1/2 barrel before the second meeting with the garden, 3/2 barrel before the second meeting with the restaurant, 3/4 barrel before the first meeting with the garden and 7/8 barrel before the first meeting with the restaurant. This is the answer. ( 1/3x- 1/5x)* 3 =( 1- 1/3- 1/5)x- 16/ 15x = 7/65438