The box weighs 120 pounds and she's going to use half of it to make applesauce so she'll use 120/2 = <<120/2=60>>60 pounds for applesauce
The box weighs 120 pounds and she'll use 60 pounds for applesauce so that leaves 120-60 = <<120-60=60>>60 pounds of apples
She has 60 pounds of apples and she needs 4 pounds to make a pie so she can make 60/4 = <<60/4=15>>15 pies
#### 15