Is the series `3 + 33 + 333 + `….a Geometric series ?

Find the sum of first n terms and the sum of first 5 terms of the geometric series 1+ 2/3 +4/9 +............

The 1^(st) , 2^(nd) and 3^(rd) terms of an arithmetic series are a , b and a^(2) where 'a' is negative. The 1^(st) , 2^(nd) and 3^(rd) terms of a geometric series are a , a^(2) and b respectively. The sum of the 40 terms of the arithmetic series is

If first three terms of the sequence 1//16 ,a , b , c1//16 are in geometric series and last three terms are in harmonic series, then find the values of aa n dbdot

Find the sum of the Geometric series 3+6+12+…1536 .

The sum of first n terms of a certain series is given as 3n^(2)-2n . Show that the series is an arithmetic series.