Jules has to earn $200 because 1000 / 5 = <<1000/5=200>>200
He has earned $40 from starting the walks because 20 x 2 = <<20*2=40>>40
He has to earn $160 from distance, because 200 - 40 = <<200-40=160>>160
He has to walk 128 blocks because 160 / 1.25 = <<160/1.25=128>>128
#### 128