human
Julia bought 3 packs of red balls, 10 packs of yellow balls, and 8 packs of green balls. There were 19 balls in each package. How many balls did Julie buy in all?
assistant
How many packages were there? ** The total number of packages is 3 + 10 + 8 = <<3+10+8=21>>21.
How many balls did Julia buy in all? ** Julia bought 21 × 19 = <<21*19=399>>399 balls.
#### 399