Answer:
The sister's present age is 8 years old, and the brother's present age is 4 years old.
Step-by-step explanation:
Let
present age of the brother,
present age of the sister
× 
= 

×

(proved from above equations)



×

the brother's present age is 4 years old, and the sister's present age is 8 years old.
Hope this helps :)