John decides to start collecting art.  He pays the same price for his first 3 pieces of art and the total price came to $45,000.  The next piece of art was 50% more expensive than those.  How much did all the art cost?
The first 3 pieces each cost 45000/3=$<T>divide(45000, 3)=15000.0
So the next piece was 15,000*.5=$<T>multiply(15000, 0.5)=7500.0 more expensive
That means it cost 15,000+7,500=$<T>add(15000, 7500)=22500
That means in total he spent 45,000+22,500=$67,500
,500