Answer
$15$
Work Step by Step
$\sum ^{\infty }_{n=0}5\left( \dfrac {2}{3}\right) ^{n}=5\sum ^{\infty }_{n=0}\left( \dfrac {2}{3}\right) ^{n}=\lim _{n\rightarrow \infty }5\times \left( \dfrac {1-r^{n}}{1-r}\right) =5\times \left( \dfrac {1-\left( \dfrac {2}{3}\right) ^{n}}{1-\dfrac {2}{3}}\right) =5\times \dfrac {\left( 1-0\right) }{1-\dfrac {2}{3}}=15$
