Tim decides to get animals for his zoo.  He buys 3 goats for $400 each.  He gets twice as many llamas which cost 50% more each.  How much did he spend?
The goats cost 3*400=$<T>multiply(3, 400)=1200
He buys 3*2=<T>multiply(3, 2)=6 llamas
Each llama cost 400*1.5=$<T>multiply(400, 1.5)=600.0
So he spends 600*6=$<T>multiply(600, 6)=3600 on llamas.
So the total cost was 1200+3600=$<T>add(1200, 3600)=4800
