If the standard price is 12 dollars and the price for groups is 3 dollars less (12 - 3 = 9 dollars) per person, then in 30-people group the total price would be 9 * 30 = 270 dollars .
The total cost for a class of 30 students with the group discount is $270. This is calculated by applying a $3 discount to the standard price of $12, resulting in a cost of $9 per student. Multiplying this cost by the number of students gives the total cost as $270.
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