$5+4=9$ 
Peter bought three apples of $5$ dollars, and $4$ bananas of $4$ dollars. How much did he spend in total?~(adapted from $$2011$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$7$$) 
  * $$6$$ dollars 
  * $$7$$ dollars 
  * $$8$$ dollars 
  * $$9$$ dollars 
  * $$10$$ dollars 