$$1-135\div180=25\textbackslash\%$$. 
A jacket was on sale. The original price was ＄$$180$$, and Peter bought it at ＄$$135$$. What was the discount? 
(1) $$135\textbackslash\%$$ 
(2) $$180\textbackslash\%$$ 
(3) $$75\textbackslash\%$$ 
(4) $$25\textbackslash\%$$ 