John decides to trade in his stereo system.  His old system cost 250 dollars and he got 80% of the value for it.  He then buys a system that costs $600 that he gets a 25% discount on.  How much money came out of his pocket?
He got 250*.8=$<T>multiply(250, 0.8)=200.0
He gets a 600*.25=$<T>multiply(600, 0.25)=150.0 discount on the second system
So it cost 600-150=$<T>subtract(600, 150)=450
So he was 450-200=$<T>subtract(450, 200)=250 out of pocket
