Mike has to get an x-ray and an MRI.  The x-ray is $250 and the MRI is triple that cost.  Insurance covers 80%.  How much did he pay?
The MRI cost 250*3=$<T>multiply(250, 3)=750
So between the two things he pays 250+750=$<T>add(250, 750)=1000
Insurance covered 1000*.8=$<T>multiply(1000, 0.8)=800.0
So he had to pay 1000-800=$<T>subtract(1000, 800)=200
