Jon's laundry machine can do 5 pounds of laundry at a time.  4 shirts weigh 1 pound and 2 pairs of pants weigh 1 pound.  If he needs to wash 20 shirts and 20 pants, how many loads of laundry does he have to do?
The shirts weigh 20/4=<<20/4=5>>5 pounds
The pants weigh 20/2=<<20/2=10>>10 pounds
So he needs to do 10+5=<<10+5=15>>15 pounds of laundry
So that would take 15/5=<<15/5=3>>3 loads of laundry
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