42/2 = <<42/2=21>>21 raspberries had been picked.

42/3 = <<42/3=14>>14 blackberries had been picked.

21+14 = <<21+14=35>>35 raspberries and blackberries had been picked.

42-35 = <<42-35=7>>7 blueberries had been picked.

# Answer

7
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
42 raspberries, blackberries, and blueberries were picked in total. If half of all the berries had been raspberries, and a third of the berries were blackberries, how many of them were blueberries?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
7
42 raspberries, blackberries, and blueberries were picked in total. If half of all the berries had been raspberries, and a third of the berries were blackberries, how many of them were blueberries?
train