Hello, thank you for taking the time to post your question!
When you are computing the percentage increase you want to take
% Increase = (New – Old)/Old x 100%
For this question that becomes
(225 – 75)/75 x 100%
=150/75 x 100%
=2 x 100%
=200%
I hope that helps get you moving in the right direction! Feel free to reach out if you have any additional questions beyond that :)