Question 39348
Common ratio...the number you multiple a term by to generate the next term.


1*3 is 3
3*3 is 9
9*3 is 27


--> r is 3


b. 
1st term of a GP = a
2nd term of a GP = ar
3rd term of a GP = {{{ ar^2 }}} and so,
nth term of a GP = {{{ ar^(n-1) }}}


So, 10th term is {{{ (1)(3)^(10-1) }}}
{{{ (3)^(9) }}}
19683


c. Sum of n terms = {{{ (a(r^n-1))/(r-1) }}}
{{{ ((1)((3)^10-1))/(3-1) }}}
{{{ (3^10-1)/2 }}}
{{{ (59049-1)/2 }}}
29524


jon.