Question
There was an equal number of black and pink balls in a bag at first. After 30 pink balls were taken out and 30 black balls were added into the bag, there was 15 as many pink balls as black balls. Find the number of pink balls in the bag at first.
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There was an equal number of black and pink balls in a bag at first. After 30 pink balls were taken out and 30 black balls were added into the bag, there was 15 as many pink balls as black balls. Find the number of pink balls in the bag at first.