Ben's family caught 4 + 1 + 3 + 2 + 5 = <<4+1+3+2+5=15>>15 fish.
They kept 15 - 3 = <<15-3=12>>12 fish.
They'll get 2 filets per fish, so they will have 12 fish * 2 filets per fish = <<12*2=24>>24 filets.
#### 24