On Tuesday Buddy has 30/2 = <<30/2=15>>15 baseball cards.
On Wednesday Buddy has 15+12 = <<15+12=27>>27 baseball cards.
On Thursday Buddy buys 15/3 = <<15/3=5>>5 baseball cards.
On Thursday Buddy has a total of 27+5 = <<27+5=32>>32 baseball cards.
#### 32