Aveterinarian purchases some medication for $19.50 and wants to make a $2 profit. what is the percent markup on this medication

So he has to sell it at 19.5+2=21.5 dollars

so assume19.5=100%
the markup is 2 dollars
2=x%
find x if 19.5=100%

so since they are proportionite
19.5:100 and 2:x
if we make them fractions and flip one of them then multiply we will get 1 since
2/4=1/2
2/4 times 2/1=4/4=1 so

19.5/100 times x/2=19.5x/200=1
19.5x/200=1
multiply both sides by 200
19.5x=200
divide both sdies by 19.5
x=10.256 aprox
x=10.3% markup

69 i think because is the only one square