Answer:
20%
Step-by-step explanation:
The percentage of the concentration can be calculated by dividing the amount of solute by the total amount of the solution. In this case the solute would be the 20g of medication while the total solution amount is 100ml. Therefore, we divide these two values like so...
20 / 100 = 0.20
This is the percentage in decimal form, we can now multiply it by 100 to get the percentage value (which in this scenario is simply reversing the previous division)
0.20 * 100 = 20%
