( value of adult ticket [3.50]* number of adult tickets [x]) + (value of student ticket [2.50] * number of student tickets [y]) = total value (1237.50)
425 = x + y
(number of adult tickets [x]) + (number of student tickets [y]) = total (425)
The president can be elected in 28 different ways. After a student is elected president, there are 27 students left to elect a vice president from. So there are 28 x 27 = 756 different arrangements.
