Ellen is baking bread. It takes 3 hours to rise 1 ball of dough, and then another 2 hours to bake it. If she makes 4 balls of dough one after another and then bakes them one after another when they're done rising, how many hours will it take?
Ellen takes 4*3=<<4*3=12>>12 hours in total to rise all balls of dough.
It will take 4*2=<<4*2=8>>8 more hours to bake each one.
It will take her 12+8=<<12+8=20>>20 hours to make all of the bread.
#### 20