You are given a compound which calls for combining 30 grams of 2.5% hydrocortisone cream with 15 grams of zinc oxide

To combine 30 grams of 2.5% hydrocortisone cream with 15 grams of zinc oxide, you first need to understand how to calculate the amount of each ingredient based on their percentages.

For the hydrocortisone cream, you have 2.5% hydrocortisone and 97.5% other ingredients. This means that in every 100 grams of the cream, 2.5 grams is hydrocortisone and the remaining 97.5 grams is other ingredients.

To find the amount of hydrocortisone in the 30 grams of cream required, multiply 30 grams by 2.5% (or 0.025). This calculation gives you 0.75 grams of hydrocortisone.

Next, you need to calculate the amount of zinc oxide. Since the zinc oxide is given as 15 grams, you do not need to make any additional calculations for this ingredient.

Overall, you would combine 0.75 grams of hydrocortisone cream with 15 grams of zinc oxide to get your compound.