John reels in 3 crab baskets a week.  Each basket holds 4 crabs.  He collects crabs twice a week.  Each crab sells for $3.  How much money does he make?
He collects 3*4=<<3*4=12>>12 crabs each time.
He thus collects 12*2=<<12*2=24>>24 crabs a week.
So he makes 24*3=$<<24*3=72>>72 a week.
#### 72