The value of a machine, V $,$ at the end of t years is given by V$=$C$(1$r$)$t

$,$ where C is the original cost of the machine and r is the rate of depreciation. A machine that originally cost $$20,700$

is now valued at $$13,515$

$.$ How old is the machine if r$=0\mathrm{.}11$

$?$ Round your answer to two decimal places.