###Human: Julia had to make 6 cakes for the party. Each cake takes 12 minutes to mix and needs 9 more minutes to bake than mix. Then it takes 6 more minutes to cool and decorate than to bake. How many hours will it take to make all 6 cakes?, ### Assistant: It takes 12 + 9 =21 minutes to bake each cake.
It takes 21 + 6 = 27 minutes to cool and decorate each cake.
Therefore, it takes a total of 12 + 21 + 27 = 60 minutes to make one cake.
Thus, it takes 60/60 = 1 hour to bake one cake.
So, it will take 1 x 6 = 6 hours to bake all 6 cakes. 
 So the answer is :  6