20:
[tex]20 + 10\% = 22 \\ 20 - 50\% = 10 \\ 20 - 20\% = 16 \\ 20 + 25\% = 25[/tex]
60:
[tex]60 + 10\% = 66 \\ 60 - 50\% = 30 \\ 60 - 20\% = 48 \\ 60 + 25\% = 75[/tex]
150:
[tex]150 + 10\% = 165 \\ 150 - 50\% = 75 \\ 150 - 20\% = 120 \\ 150 + 25 \% = 187.5[/tex]
300:
[tex]300 + 10\% = 330 \\ 300 - 50\% = 150 \\ 300 - 20\% = 240 \\ 300 + 25\% = 375[/tex]