So first lets do the fraction: 68/80. This is probably the most simple part, but if you want to simplify it you could go all the way down to 17/20.
For decimalthen you divide 68 by 80, and that is .85! Then to get your percentage, you multiply it by 100 and end up with 85%.
Percent: 85%
Fraction: 68/80 or 17/20
Decimal: 0.85
Hope this helps!