Jawabanmu

2014-02-18T15:55:05+07:00
A = 20 ; r =  \frac{1}{5}

Sn =  \frac{a}{1-r}
Sn =  \frac{20}{1- \frac{1}{5} }
Sn =  \frac{20}{ \frac{4}{5} }
Sn = 25