First find how thick the blanket will be after 1 folding: 3 inches * 2 = <<3*2=6>>6 inches
Then find how thick the blanket will be after 2 foldings: 6 inches * 2 = <<6*2=12>>12 inches
Then find how thick the blanket will be after 3 foldings: 12 inches * 2 = <<12*2=24>>24 inches
Then find how thick the blanket will be after 4 foldings: 24 inches * 2 = <<24*2=48>>48 inches
#### 48