1 - 0.3X
2 - 0.6 (X - 0.3X) = 0.6* 0.7X = 0.42X
3 - (X - (0.3X + 0.42X) = X - 0.72X = 0.28X
0.42X = 7.7 + 0.28X
0.14X = 7.7
X = 55
1 - 0.3X
2 - 0.6 (X - 0.3X) = 0.6* 0.7X = 0.42X
3 - (X - (0.3X + 0.42X) = X - 0.72X = 0.28X
0.42X = 7.7 + 0.28X
0.14X = 7.7
X = 55