Part A: Let x be the cost of each student and y be the cost of each teacher.
Part B: 25x + 2y = 97.5 (1)
32x + 3y = 127 (2)
Part C: Solve simultaneously.
3(1) - 2(2): 75x - 64x = 292.5 - 254
11x = 38.5
x = 38.5/11 = $3.50
Since x = $3.50, 32(3.5) + 3y = 127
112 + 3y = 127
3y = 15
y = $5
Part D: It makes sense, but let's check with the first equation to make sure it satisfies the first equation.
LHS = 25(3.5) + 2(5) = 87.5 + 10 = $97.50, which is true.
Hence, each student costs $3.50 and each teacher costs $5