Jeremy saw 12 birds in their backyard and threw a stone at them, scaring away 1/3 of that number. A few minutes later, 20 more birds joined the fearless birds. How many birds are now in the backyard?
The total number of birds scared away after he threw the stone at them is 1/3 * 12 = <<1/3*12=4>>4 birds.
The total number of birds remaining is 12 - 4 = <<12-4=8>>8 birds.
If 20 more birds joined, the total number of birds in the backyard will become 8 + 20 = <<8+20=28>>28 birds.
#### 28