\(S=\dfrac{625}{625}+\dfrac{125}{625}+\dfrac{25}{625}+\dfrac{5}{625}+\dfrac{1}{625}\)
\(=\dfrac{781}{625}\)
S = 1 + \(\dfrac{1}{5}\) + \(\dfrac{1}{25}\) + \(\dfrac{1}{125}\) + \(\dfrac{1}{625}\)
5.S = 5 +1 + \(\dfrac{1}{5}\) + \(\dfrac{1}{25}\) + \(\dfrac{1}{125}\)
5S - S = 5 - \(\dfrac{1}{625}\)
S = ( 5 - \(\dfrac{1}{625}\)) : 4
S = \(\dfrac{781}{625}\)