The unlabeled part of the right angle is complementary to 68 degrees, so 22 degrees. y is supplementary to 78 degrees, so 102 degrees. z as the third angle in the small triangle is 180 less than the sum of the other two,
z = 180 - 22 - 102
Answer: 56 degrees
All you would have to do is divide 1,845 by 10 to get the answer which is $184.50 to each classroom