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?
Reason slowly and give your answer.
7
42 / 2 = 21 raspberries had been picked.

42 / 3 = 14 blackberries had been picked.

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

42 - 35 = 7 blueberries had been picked.

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Therefore, the answer is 7