Question
In a hall, 310 of the pupils wore vests. After 75 pupils who wore vests entered the hall, the percentage of pupils who wore vests increased to 80%. How many pupils in the hall did not wear vests?
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In a hall, 310 of the pupils wore vests. After 75 pupils who wore vests entered the hall, the percentage of pupils who wore vests increased to 80%. How many pupils in the hall did not wear vests?