2 children sold 4 apples each which gives 2*4 = <<2*4=8>>8 apples
Another child gave out an additional 7 apples making 8+7 = <<8+7=15>>15 apples removed from the total
There were 60 apples left after these, so the original total must have been 15+60 = <<15+60=75>>75 apples
Each child collected 15 apples so there are 75/15 = 5 children
#### 5