Sembilan tahun lalu, umur A : umur B = 1 : 3. Sekarang umur B : C = 1 : 3. Sembilan tahun mendatang, umur A : umur C = 1 : 3. Berapa umur A , B, C saat ini ?

9th lalu, A : B = 1 : 3
A = 3th & B = 3th umur A x 3 = 9th
sekarang, B : C = 1 : 3
B = 9th umur B + 9th lalu = 18th & C = 18th umur B x 3 = 54th
9th mndtng, A : C = 1 : 3
A = 3th umur A + 9th lalu + 9th mndtng = 21th & C = 21th umur A x 3 = 63th
A = 3th + 9th = 12th
B = 18th
C = 54th