(1 - 0.75)x =(1 - 0.8)(54 - x)
0.25x = 0.2(54 - x)
0.25x = 10.8 - 0.2x
0.25x + 0.2x = 10.8
0.45x = 10.8
x = 10.8 ÷ 0.45
x = 24