$(12 + 4) \div 2 = 8$ 
Debbie spent $12$ dollars on a book and a volleyball. The volleyball costed $4$ dollars than the book. How many dollars did she spend on the volleyball? 

1: $$4$$ 
2: $$5$$ 
3: $$6$$ 
4: $$7$$ 
5: $$8$$ 