13-8 is $5 difference
So the mark up is the $5 from the $8
So 100%=8
And ?%=13
So just looking the mark up should be around 60% because 5 is a little bit more than half of 8
So to find the actual markup, divide 5 by 8 = 0.625
Which is 62.5%
So
8=100%
13=162.5%
5=62.5% which is the mark up.
Good luck
Brainliest would be greatly appreciated