If Hiram's age is 40, when you add 12, his age becomes 40+12=<<40+12=52>>52
If you add 4 from Hiram's age after adding twelve to his age, you get 52+4 = 56, which is twice Allyson's age.
Allyson's age is 56/2 = <<56/2=28>>28 years
#### 28