Ratios and Proportions Jessica Tagerman, PharmD, RPh 1
Use ratios and proportions to solve the following problems. 1. Calculate the value of x to form a proportion a. 2/3 and 4/x b. 5/7 and 15/x c. x/5 and 10/25 d. 3/5 and x/100 e. x/7 and 6/42 2. How many tablets will be taken in 10 days if a prescription order reads Zaleplon 5 mg/tablet, one tablet daily at bedtime? 3. How many tablets are needed to fill a prescription for 34 days of zidovudine 100mg/tablet, one tablet twice daily? 4. How many tablets will be taken in 10 days if a prescription order reads metoclopramide 5 mg/tablet, one tablet three times a day? 2
5. How many capsules are needed for fill a prescription for 14 days for ampicillin 500 mg/capsule, one capsule four times a day? 6. How many mg will be taken over 34 days if a patient takes one metoclopramide tablet (5 mg) every day? 7. Becky fills 50 prescriptions in 1 hour. How many prescriptions does Becky fill in: a. 2 hours? b. 4 hours? c. 6.5 hours? d. ½ hour? e. 7.895 hours? 3
8. Mary drove her car 110 miles in 2 hours. a. Express this value as a mathematical ratio. b. What is her speed? (How many miles is she driving in 1 hour?) c. How many miles will she drive in 3 hours? d. Mary is tired from driving, but wants to drive 600 miles before she takes her first break. How many hours will it take her to drive 600 miles? 9. CPhT Julia Roberts is working at a hospital when she receives the following prescription: Patient Name: Richard Gere Address: 123 Madeup Lane, Deerfield IL 60015 Rx Fentanyl Citrate Injection Inject 0.05 mg IM stat Signature: Carey Lowell,, MD a. Interpret the sig b. How many ml of the drug will be injected? 4
10. The dosing for a pediatric medication is dependent on a child s age and weight. For a child from newborn to 6 months, the dose is 4 mg/kg, and for a child from 6 months to 3 years, the dose is 6 mg/kg. Zachary Bernheim is 23 weeks old and weights 14.5 lbs. You need to calculate the needed dose. a. List the steps you ll use to solve this problem. b. Set up a proportion and determine Zac s dose of this medication. 11. A 15 ml multi dose vial of medication costs $1000. Each dose is 1.5 ml. a. How many doses are in the vial? b. How much will 6 doses of medication cost? c. What is the cost of each medication dose? 5
12. The dosing of medication A is dependent on a patient s weight. The medication comes in vials of 150 mg/ 3 ml, and dosing is as follows: 0 30 kg = 100 mg 30 90 kg = 200 mg 90 120 kg = 400 mg. Please calculate the dosage, and therefore, the volume of medication each patient will receive: a. Nick Jonas, 165 lbs. b. Elmo, 3 kg. c. Peter Griffin, 250 lbs. 13. The infusion rate of an IV is 300 ml over 5 hours. What is the ml/minute rate? 14. Each tablet of amoxicillin contains 500 mg of the active ingredient. The antibiotic prescription calls for a patient to take 2000 mg of the drug. How many tablets should be dispensed? 15. If one teaspoonful is equal to 5 ml, then 30 ml is how many teaspoonfuls? 6
16. A one month supply of Celecoxib (#30 tablets), a COX 2 inhibitor, costs $717.80. A patient only has $600, and would like to know how many capsules he can purchase. He currently takes one capsule daily. 17. How many tablets need to be dispensed if a prescription calls for 3 mg of Drug K every 6 hours for 14 days, and the only strength of Drug K we have in stock is 1.5 mg/tablet? The physician has approved the use of the 1.5 mg tablet. 18. You are planning a brownie party for the pharmacy technician class! Everybody is VERY hungry. On average, one batch of brownies makes 12 pieces. There are 6 students and one instructor. How many batches should you make if everybody is going to eat: a. 3 pieces b. 4 pieces c. 10 pieces d. 1 batch each 19. Omeprazole costs $289 per 30 capsules. How much do the following quantities cost? a. 90 capsules 7
b. 15 capsules c. 17 capsules d. 7 capsules e. 1 capsule 20. Brad Pitt brings in a prescription with the following instructions. T 1 tab po q4 6h prn pain. How many tablets should be dispensed for: a. 20 days b. 30 days c. 60 days d. 75 days 8
e. 90 days 21. If 5 tablets of Lipitor contain 20 grams of Lipitor, how many tablets are required to fill a prescription for 500 grams? 22. A patient uses an eye drop with the directions 2 drops in each eye twice a day. a. How many drops does she use each day? b. How many drops does she use in 5 days? c. How many drops will she use in 17 days? 23. Drug X 458 grams is the active ingredient used to make 150,000 tablets. What is the strength, in mg, of one tablet? 24. A vial of Protonix contains 40 mg/3.5 ml. What volume of Protonix contains 15 mg? 25. Normal saline solution contains 0.9 g sodium chloride in 100 ml. How much sodium chloride is contained in.. a. 250 ml? b. 750 ml? 9
c. 2 L? d. 1.5 L? 10