Answer:
Decrease by 20%.
Step-by-step explanation:
We have to find the percent of increase or decrease from n to [tex]\frac{4}{5}n[/tex].
Now, [tex]\frac{4}{5}n = 0.8n < n[/tex]
So there is a decrease fro n to [tex]\frac{4}{5}n[/tex].
Now, the percentage of decrease will be given by
= [tex][ \frac{\textrm {Original Value - Final Value}}{\textrm {Original Value}}]\times 100 \%[/tex]
= [tex][ \frac{n - 0.8n}{n}]\times 100 \%[/tex]
= 20% (Answer)