Answer
(a) $\frac{4}{5}$ or 80% or 0.8
(b) $\frac{1}{5}$ or 20% or 0.2
Work Step by Step
(a)
Reduce $\frac{64}{80}$ by 16 to get $\frac{4}{5}$
$\frac{1}{5}$=0.2 so $\frac{4}{5}$=4$\times$0.2=0.8
0.8=80%
(b)
1-$\frac{4}{5}$=$\frac{1}{5}$
1-0.8=0.2
100%-80%=20%
