I love listening to music from the 80s.

I love listening to 80s music.

I found a box full of Trash-80s in the attic.

I love listening to music from the 80's.

I found an old Trash-80 computer in the attic.

The 80-20 rule, also known as the Pareto principle, states that 80% of the results come from 20% of the efforts.

The 20-80 rule, also known as the Pareto principle, states that 20% of the input or effort produces 80% of the results.