could you please help me

A movie theater has a seating capacity of 215. The theater charges $5.00 for children, $7.00 for students, and $12.00 of adults. There are half as many adults as there are children. If the total ticket sales was $ 1554, How many children, students, and adults attended? Hint. Let a be number of adults and c the number of children. Then "There are half as many adults as there are children" means that "the number of adults is half the number of children", or a = 1 = 2 C , or 2a = c. children attended. students attended. adults attended