it doesn't. Why would you think it does? It is equivalent to 30/5= 6. 30/500 is the same as 6%.

That is the fraction 52/80 which you can reduce to 13/20 (by dividing both numerator an denominator by 4). Dividing 13 by 20 (or dividing 52 by 80) we get .65 (another way to do this is to multiply numerator and denominator of $\displaystyle \frac{13}{20}$ by 5 to get $\displaystyle \frac{65}{100}= .65$). Multiplying that by 100 gives 65%.

The fraction is $\displaystyle \frac{432p}{720p}$. You can simply divide that, by long division or using a calculator, to get 0.6 which, multiplying by 100, gives 60%. If you like, you can reduce the fraction a bit first: $\displaystyle \frac{432}{720}= \frac{27}{45}$ (dividing numerator and denominator by 16) and then $\displaystyle \frac{3}{5}$ (dividing numerator and denominator by 9) which also gives .6.