1: 80% The reason why is because if you do 4/5, you get .80, move the decimals to places to the right, and you get 80%
2: 95% Process of Elimination, and Educated Guess.
3: 33 1/3% If you do 50/150, you get 0.33333... Like I said, move the decimal point two places to the right, and you get 33.33...%
I hope this helps, and Happy Holidays! :)