Do you subtract Tax medicare levy before tax deductions or after ? (financial Mathematics)

Matteo makes raspberry punch. the table shows how many parts ginger ale and raspberry juice to use for a batch. raspberry punch parts ginger ale 2 parts raspberry juice 3 matteo decides to add one part of raspberry juice. what is the new ratio of ginger ale to raspberry juice?

Answer this question only if you know the 30 points and

Write the rational number in lowest terms 99/-15