Jawabanmu

2014-04-05T00:43:43+07:00
Jawaban paling cerdas!
2014-04-05T00:53:11+07:00
 r^{n-1} = 30 ×  2^{8-1}
 r^{n-1} = 30 ×  2^{7}
 r^{n-1} = 30 × 128
 r^{n-1} = 3840 amuba

kalau benar terbaik ya