First, make 18 over 25 another fraction over 100
To make 25 a 100, multiply it by 4 and do the same to the numerator, or 18.
You end up with 72 over 100, then make it a decimal
0.72
Them move the point 2 spaces to the right for the percent
72%
Mark got 72% of the questions correct
Mark brainliest if this helped :)