Final answer:
To obtain 75 grams of phenylephrine hydrochloride from Dristan tablets with a dosage of 5mg per tablet, 15,000 tablets would be required.
Step-by-step explanation:
The student's question asks how many Dristan tablets containing 5mg of phenylephrine hydrochloride would be needed to have a total of 75 grams. To find the required number of tablets, we need to convert the total amount desired (75 grams) to milligrams, since the dosage per tablet is given in milligrams.
There are 1,000 milligrams in a gram, so 75 grams is equal to 75,000 milligrams. If each tablet contains 5mg, then you would divide the total amount needed (75,000 mg) by the amount per tablet (5mg): 75,000 mg / 5mg = 15,000 tablets.
Therefore, you would need 15,000 tablets of Dristan to achieve a total of 75 grams of phenylephrine hydrochloride.