Find the sum of n terms of the following series :
(i) 5+55+555+…
(ii) 4+44+444+…
(iii) 0.3+0.33+0.333+…
(iv) 0.7+0.77+0.777+…

Answer

(i)`(5)/(9){(10(10^(n)-1))/(9)-n}`
(ii)`(4)/(9){(10(10^(n)-1))/(9)-n}`
(iii)`(n)/(2)-(1)/(27){1-(1)/(10^(n))}`
(iv)`(7n)/(9)-(7)/(81){1-(1)/(10^(n))}`

Explanation

N/a