Jawabanmu

2014-09-02T14:38:34+07:00
Memakai perbandingan senilai..
 6/9 = 20/x
x = 30 m. selesai =)
2014-09-02T14:39:49+07:00
T = 6m , t = 9m
T = 20m, t ...?
->  6 = 20
     9     x
6x = 20.9
6x = 180
x = 30