Being women half of the guests, there were 50/2 = <<50/2=25>>25 women in the movie screening.
Adding the 15 men to the number of women guests, there were 25 + 15 = <<25+15=40>>40 men and women.
From a total of 50 guests, 50 - 40 = <<50-40=10>>10 were children.
Knowing 1/5 of the men left, 15/5 = <<15/5=3>>3 men left.
Thus, 3 men + 4 children = <<3+4=7>>7 people left in all.
Therefore, 50 - 7 = <<50-7=43>>43 people stayed.
#### 43