To answer this question we will use the following expression to compute the y% of x:
[tex]x*\frac{y}{100}.[/tex]Therefore the 13% of 75 is:
[tex]75*\frac{13}{100}.[/tex]Simplifying the above result we get:
[tex]3*\frac{13}{4}=9.75.[/tex]Therefore there are 9.75 g of drug in 75g of a 13% preparation.
Answer: 9.75g.
