First divide the total number of businesses by 2 to find how many businesses Brandon hasn't been fired from: 72 businesses / 2 = <<72/2=36>>36 businesses
Then divide the total number of businesses by 3 to find how many businesses Brandon quit from: 72 businesses / 3 = <<72/3=24>>24 businesses
Then subtract that number from the number of businesses he hasn't been fired from to find the number of businesses where he can still apply: 36 businesses - 24 businesses = <<36-24=12>>12 businesses
#### 12