He has 3 hours to read because 8 - 3.5 - 1.5 = <<8-3.5-1.5=3>>3
He has 180 minutes to read because 3 x 60 = <<3*60=180>>180
He can read 1,800 words because 180 x 10 = <<180*10=1800>>1,800
#### 1800