If Benny is 12 right now, that means that he is twice his sisters age because he is 200% of or 2 times his sister's age. His sister right now is 6 years old then. After 4 years, Benny will be 16 (add 4 to 12) and his sister will be 10. To find the percentage,divide his age by his sister's age and make it a percentage. 16/10=1.6=160% Hope this helps.