Always the % number is have to be over 100 5/100=5%
ex. 39%=39/100
45 we do not know what is it so we put (y) 45/y or any other letter
now we put them together
5/100=45/y
we solve for y
5y=100x45
5y=4500 divide by 5
y=900
That is the answer I hope it is helpful