2.5 * 5 = <<2.5*5=12.5>>12.5 hours
0.5 * 3 = <<3*0.5=1.5>>1.5 hours
12.5 + 1.5 hours = <<12.5+1.5=14>>14 hours
14 hours = 14 * 60 = <<14*60=840>>840 minutes
It would take 840 minutes to groom 5 dogs and 3 cats.
#### 840