Answer:
1/80
Step-by-step explanation:
(ab²)^-3 = (a^-3)(b^-6) = [tex]\frac{1}{5}[/tex]b^6
[tex]\frac{1}{5}[/tex]b^6 = 1 /[5(b³)²] = 1 / (5·4²) = 1/80