Witold says that 50% of a number will always be greater than 20% of any other number.

50% of a number will always be greater than 20% of ANY other number
that is false
just find one counter statement where it is false

so
50% of 1 if 0.5
20% of 100 (another number) is 20
0.5>20 is false

tada

Here, feel free to ask if there are any questions