The silver rocket exploded $(20-6)\div2=7$ stars, and the gold rocket exploded $20-7=13$ stars. 
Denise fired a silver rocket and a gold rocket at the same time. The rockets exploded into $20$ stars in total. The gold rocket exploded into $6$ more stars than the silver one. How many stars did the gold rocket explode into? (2021 Math Kangaroo Problem, Level 3-4, Question \#7) 

(1) $$9$$ 
(2) $$10$$ 
(3) $$12$$ 
(4) $$13$$ 
(5) $$15$$ 