He wants to serve 5 hushpuppies to each guest and he is having 20 guests so that's 5*20 = <<5*20=100>>100 hush puppies
He can only cook 10 hushpuppies at a time and he needs to cook 100 hushpuppies so that's 100/10 = <<100/10=10>>10 batches of hushpuppies
Each batch takes 8 minutes to cook and he has 10 batches to cook so it will take him 8*10 = <<8*10=80>>80 minutes
#### 80