(2^3/5*5^2/3)^15/10^9

[tex] \frac{(2^{ \frac{3}{5}} *5^{ \frac{2}{3} })^{15}}{10^9} =\frac{2^{ \frac{3*15}{5}} *5^{ \frac{2*15}{3} }}{10^9} == \frac{2^9*5^{10}}{5^9*2^9}=5 [/tex]