Practice Problems Answers and Rationales

1. Convert 3/4 to decimal form

0.75 (divide 3 by 4)

2. Convert 80 percent to decimal form

0.8 (move decimal point over two places to left when converting from percentage to decimal)

3. Round to the nearest hundredth: 0.995

1 (rounding up requires carrying over to next place if the number goes up to 10)

4. Round to the nearest tenth: 12.38

12.4 (the 8 makes the 3 round up)

5. Round to the whole number: 3.4

3 (the 4 doesn't allow for rounding up)

6. Solve: 0.01 x 0.01 = 

0.0001 (move decimal of 0.01 over two places to the left)

7. Solve: 1.23 x 100 = 

123 (move decimal point two places to right)

8. Solve: 1,000 x 0.1 =

100 (move decimal point one place to left)

9. Solve: 8.5 x 0.001 =

0.0085 (move decimal point 3 places to left)

10. Solve: 1.5/2 =

0.75 (half of 1.5 if 0.75)

1. Convert 2 mg to mcg

2,000 mcg (move decimal 3 places to the right)

2. Convert 125 mcg to mg

0.125 mg (move decimal point 3 places to the left)

3. Convert 2 g to mg

2,000 mg (move decimal 3 places to right)

4. Convert 125 pounds to kg

56.8 kg rounded to tenth (125/2.2)

5. Convert 30 pounds to kg

13.6 kg rounded to tenth (30/2.2)

6. Convert 8 fluid oz to ml

240 ml (each fluid once = 30 ml)

7. Convert 1 cup to ml

240 ml (1 cup = 8 fluid ounces = 240 ml)

8. Convert 2 tablespoon to ml

30 ml (each tablespoon equals 15 ml)

9. Convert 5 ft 10 in to cm

177.8 cm (Convert to inches first, then multiply by 2.54)

10. Convert 4 ft 8 in to cm

142.24 cm (Convert to inches first, then multiply by 2.54)

1. Order for warfarin 2 mg oral daily.  Available is warfarin 4 mg tablets.  What will the nurse administer?

0.5 tab PO (2 mg/4 mg x 1 tab = 0.5 tab)

2. Order for aspirin 324 mg oral for chest pain.  Available is aspirin 81 mg tablets.  What will the nurse administer?

4 tab PO (324 mg/81 mg x 1 tab = 4 tab)

3. Patient is having anxiety.  There is a prn order for prochlorperazine 10 mg PO every 8 hours for nausea/vomiting.  Available from pharmacy is prochlorperazine 5 mg tablets.  What will the nurse administer?

Do Not Give (Dose is ordered for nausea/vomiting, not for anxiety)

4. Morphine 5 mg IV is ordered for a patient in pain.  Pharmacy supplies morphine 10 mg/ml.  What will the nurse administer?

0.5 ml IV (5 mg/10 mg x 1 ml = 0.5 ml)

5. Order for lisinopril 20 mg PO daily.  Available from pharmacy is enalapril 10 mg tablets.  What will the nurse administer?

Do Not Give (lisinopril and enalapril are not the same drug)

6. Order for heparin 5,000 units SQ.  Available is heparin 5,000 units/ml for injection.  What will the nurse administer?

1 ml SQ (5,000 units/5,000 units x 1 ml = 1 ml)

7. Patient is having a fever of 101.5 degrees F.  Order for acetaminophen 650 mg PO for fever over 100.5 degrees F.  Available from pharmacy is acetaminophen 325 mg tablets.  What will the nurse administer?

2 tab PO (650 mg/325 mg x 1 tab = 2 tab)

8. Order for digoxin 0.25 mg PO.  Available is digoxin 125 mcg tablets.  What will the nurse administer?

2 tab PO (Convert mg to mcg first - 0.25 mg = 250 mcg, then 250 mcg/125 mcg x 1 tab = 2 tab)

9. Order for furosemide 20 mg IV.  Available is furosemide 10 mg/ml.  What will the nurse administer?

2 ml IV (20 mg/10 mg x 1 ml = 2 ml)

10. Patient is having nausea.  Order for ondansetron 4 mg IV every 8 hours prn nausea.  Available is ondansetron 4 mg tablets.  What will the nurse administer?

Do Not Give (Medication is supplied as oral form, not IV)

1. Patient with ear infection weighs 22 pounds.  Order for amoxicillin 225 mg PO every 12 hours.  Safe dose is 45 mg/kg/day in two divided doses.  Available is amoxicillin 200 mg/5 ml suspension.  What will the nurse administer?

5.6 ml PO (Weight = 10 kg; 10 x 45 mg= 450 mg/day; 450 mg/2 = 225 mg/dose; safe; 225 mg/200 mg x 5 ml = 5.6 ml after rounding)

2. A patient weighing 180 pounds is getting readied for cardiovascular surgery.  Ordered is heparin IV 20,000 units.  The safe range for this medication for this procedure is 150 to 400 units/kg.  Heparin 5,000 units/ml is available.  What will the nurse administer?

4 ml IV (Weight = 81.8 kg; 81.8 x 150 units = 12,270 units for low limit and 81.8 x 400 units = 32,720 units high limit; 20,000 units is safe; 20,000 units/5,000 units x 1 ml = 4 ml

3. Methylphenidate 10 mg PO daily is ordered for a 73.33 pound adolescent suffering from attention deficit disorder.  The safe dose is 0.3 mg/kg/day.  Available is methylphenidate 20 mg tablets.  What will the nurse administer?

0.5 tab PO (Weight = 33.3 kg; 33.3 x 0.3 mg = 9.99 mg/day... which is rounded to 10 mg; 10 mg is safe; 10 mg/20 mg x 1 tab = 0.5 tab)

This was corrected from the incorrrect answer of 2 tab... kudos to Clara Bobrycki for catching the error

4. Methadone 5 mg PO every 6 hours is ordered for a patient weighing 118 pounds.  The safe range for methadone is 0.2 to 0.4 mg/kg/day in 4 divided doses.  Supplied is methadone oral concentrate 10 mg/5 ml.  What will the nurse administer?

2.5 ml PO (Weight = 53.6 kg; 53.6 x 0.2 mg = 10.72 mg/day low limit and 53.6 x 0.4 mg = 21.44 mg/day high limit; 10.72 mg/4 = 2.68 mg/dose low limit and 21.44/4 = 5.36 mg/dose high limit; 5 mg per dose is in safe range; 5 mg/10 mg x 5 ml = 2.5 ml

5. A child weighing 75 pounds has a severe skin infection and is ordered to receive daptomycin 5 mg/kg IV daily for 14 days.  The recommended dose is 5mg/kg.  Available is daptomycin 500mg/10ml.  What will the nurse administer?

3.4 ml IV (Weight = 34.1 kg; Safe and ordered dose is 34.1 x 5 mg = 170.5 mg; 170.5 mg/500 mg x 10 ml = 3.4 ml after rounding)

6. The practitioner orders ibuprofen 20 mg/kg PO every 8 hours for a child weiging 120 pounds.  The max safe dose is 2.4 g/day.  The pharmacy supplies ibuprofen oral liquid 100 mg/5 ml.  What will the nurse administer?

Do Not Give       (Weight = 54.5 kg; 54.5 x 20 = 1, 090 mg per dose... thus 1,090 x 3 = 3, 270 mg/day;  Not safe;  Do Not Give)

7. The nurse contacts the provider and the above dose is reduced to 10 mg/kg every 8 hours..  What will the nurse now administer?

27.3 ml PO          (Weight = 54.5 kg; 54.5 x 10 = 545 mg per dose... thus 545 x 3 = 1, 635 mg/day;  Safe; 545 mg/100 mg x 5 ml = 27.25 ml... rounded to 27.3 ml)

8. A child weighing 100 pounds has 12.5 mg/kg acetaminophen IV ordered every 4 hours.  The max safe dose is 3750 mg/day.  Supplied by pharmacy is acetaminophen 1000 mg/100 ml.  What will the nurse administer?

56.9 ml IV          (Weight = 45.5 kg; 45.5 x 12.5 = 568.75 mg; 568.75 x 6 = 3, 412.5 mg per day; Safe; 568.75 mg/1000 mg x 100 ml = 56.875 ml... rounded to 56.9 ml)

9. A 240 pound adult is getting ready for anesthesia and is ordered to have 0.044 mg/kg IV lorazepam to reduce any anxiety prior to the procedure.  The max safe dose is 2 mg.  Supplied from pharmacy is lorazepam for injection 2 mg/ml.  What will the nurse administer?

Do Not Give          (Weight = 109.1 kg; 109.1 x 0.044 = 4.8 mg; Not Safe; Do Not Give)

10. The nurse contacts the provider and receives an order for 0.015 mg/kg lorazepam IV for the above patient.  What will the nurse administer?

0.82 ml IV          (Weight = 109.1 kg; 109.1 x 0.015 = 1.6365 mg; Safe; 1.6365 mg/ 2 mg x 1 ml = 0.81825 ml... rounded to 0.82 ml)

1. How long will a 1 l bag last at 120ml/hr?

8 hours 20 minutes (1,000/120 = 8.3333; 8 hours + 0.333 x 60 = 20 minutes)

2. How long will a 500 ml bag last at 15 ml/hr?

24 hours (Bags can't hang for more than 24 hours)

3. The nurse hangs 1 l of NS at 17:00 with the pump set to 150 ml/hr.  When will another bag need to be hung?

23:40 (1,000/150 = 6.666 hours; 6 hours + 0.667 x 60 = 40 minutes)

4. The nurse hangs 500 ml of NS at 14:15 with the pump set to 250 ml/hr.  When will the bag be empty?

16:15 (500/250 = 2 hours) (Corrected 9/27/2022- good catch by Christa Nikiforuk for finding the mistake)

5. How many bags of 1 l LR are run in 24 hours if the pump is set to 250ml/hr?

6 (1,000/250 = 4 hours; 24 hours/4 hours = 6)

6. NS is ordered to run at 100 ml/hr.  No pump is available.  The tubing drip factor is 10 gtt/ml.  How many gtt/min will the nurse set the infusion set to?

17 gtt/min (100/60 x 10 = 17 gtt/min)

7. D5 0.45% NS is set to run at 75 ml/hr.  The pump broke.  The tubing has a drop factor of 15.  What will the nurse set the tubing drip rate to?

19 gtt/min (75/60 x 15 = 19 gtt/min)

8. IV levofloxacin 750 mg in 150 ml is ordered to run over 90 minutes.  There is no pump available.  The tubing has a drop factor of 20.  What will the nurse set the drip rate to?

33 gtt/min (150/90 x 20 = 33 gtt/min)

9. NS is running at 20 ml/hr to keep the vein open.  No pump is available.  The tubing has a drop factor of 10.  What will the nurse set the drip rate to?

3 gtt/min (20/60 x 10 = 3 gtt/min)

10. An ICU patient has an insulin drip at a rate of 10 units/hr or 10 ml/hr.  The tubing has a drop factor of 10.  What will the nurse set the drip rate to?

Do Not Give (Insulin drips need to be run via a pump... if we absolutely need to use manual drips, different tubing would need to be used with a drop factor of 60.  In that case we would have 10 gtt/min)

1. Morphine 10 mg IV is ordered for a patient in pain.  Available is morphine 5 mg/ml.  Suggested push rate is 2.5 to 15 mg over 5 minutes, undiluted.  What volume will the nurse give and how many seconds per 0.5 ml will the delivery rate be?

2 ml IV and 1.25 minutes per 0.5 ml IV (10 mg/5 mg x 1 ml = 2 ml; 2 ml/0.5 ml = 4; 5 minutes/4 = 1.25 minutes or 75 seconds)

2. Ketorolac 30 mg IV is ordered for a patient in acute pain.  Safe administration guidelines is undiluted over 15 seconds.  Supplied by pharmacy is ketorolac 15 mg/ml.  What volume will the nurse draw up and how many seconds per 0.5 ml will the delivery rate be?

2 ml IV and 3.75 seconds per 0.5 ml IV (30 mg/15 mg x 1 ml = 2 ml; 2 ml/0.5 ml = 4; 15 seconds/4 = 3.75 seconds per 0.5 ml)

3. Methylprednisolone 80 mg IV is ordered for a patient with COPD.  The safe administration for doses up to 125 mg is 5 minutes.  Supplied is methylprednisolone 40 mg vials in 2 ml sterile water.  What will the volume in the syringe be and how many ml will be delivered per minute?

4 ml IV and 0.8 ml/min IV (80 mg/40 mg x 2 ml = 4 ml; 4 ml/5 min = 0.8 ml per minute)

4. A 210 pound patient in ICU is on a dobutamine drip for cardiac stimulation.  The rate is ordered at 4 mcg/kg/min.  Supplied is doputamine 250 mg/500 ml.  What will the nurse set the infusion pump to in mcg/min and ml/hour?

381.8 mcg/min IV and 45.82 ml/hr IV (Weight = 95.45 kg; 95.45 x 4 mcg = 381.8 mcg/min; 381.8 mcg = 0.3818 mg; 0.3818 mg/250 mg x 500 ml = 0.7636 ml/min x 60 = 45.82 ml/hr)

5. A 82 kg patient in ICU is needing to be placed on a propofol drip at 5 mcg/kg/min.  Available is propofol 10 mg/ml.  What will the nurse set the pump to in mcg/min and ml/hr?

410 mcg/min IV and 2.46 ml/hr IV (82 x 5 mcg = 410 mcg/min; 410 mcg = 0.41 mg; 0.41 mg/10 mg x 1 ml = 0.041 ml/min x 60 = 2.46 ml/hr)

1. The patient is stating that her pain is 7/10.  The physician has ordered the following prn pain medications: hydrocodone/acetaminophen 5/325 mg tablet every 4 hours as needed for pain of 1-3; hydrocodone/acetaminophen 10/325 mg tablet every 4 hours as needed for pain of 4-6; hydromorphone 2 mg IV every 4 hours as needed for pain 7-10.  Available is hydrocodone/acetaminophen 5/325 mg tablets, hydrocodone/acetaminophen 10/325 mg tablets, and hydromorphone 1mg/ml for injection.  What will the nurse administer?

Hydromorphone 2 ml IV (Match the pain level with the correct medication- 7/10 = hydromorphone 2 mg IV; 2 mg/1 mg x 1 ml = 2 ml)

2. Constipation is common  when taking an opioid.  The patient has had docusate and dulcolax and is still constipated.  The physician has ordered: docusate 100 mg PO as needed for constipation; dulcolax 10 mg rectal as needed for constipation (2nd choice); magnesium hydroxide  2.4 g PO (third choice).  Available are: docusate 100 mg capsules, dulcolax 10 mg suppositories, and magnesium hydroxide 400 mg/5 ml.  What will the nurse administer?

Magnesium hydroxide 30 ml PO (The patient has already had the docusate and dulcolax, therefore we need to give the magnesium hydroxide; 2.4 g = 2,400 mg; 2,400 mg/400 mg x 5 ml = 30 ml)

3. Morphine has a half-life of about 4 hours.  If a patient takes 10 mg at 06:00, what amount will likely be in his body at 10:00 the same day?

5 mg (10 mg/2 = 5 mg)

4. Warfarin has an average half-life of 40 hours.  What amount of warfarin 6mg dose remains in the body after 80 hours?

1.5 mg (There are 2 half-lives in 80 hours; 6 mg/2 = 3 mg and then after 40 hours again... 3 mg/2 = 1.5 mg)

5. Insulin is adsorbed into infusion tubing at about a 50% amount.  If the patient absolutely needs to receive 10 units per hour, how much should the pump rate be set to? (physicians may or may not make these types of adjustments)

20 units/hour IV (If 50% is lost, the dose is doubled... follow your ICU guidelines on this)

6. A blood transfusion has 325 ml of volume and needs to be infused in 4 hours.  What is the minimum rate to get all the blood transfused in the time limit?

82 ml/hr (325/4 = 81.25 ml/hr or 81 ml/hr rounded... but the 4 hour limit is a hard stop, you will lose the last 1 ml of blood unless you round up on the rate... I know... that's why this is an extra question- it doesn't follow the rules!)

7. Another blood transfusion of 340 ml is given at a rate of 120 ml/hr for the first 15 minutes, then the rate is increased to 240 ml/hr.  How long will the transfusion take in total?

1 hour and 32 minutes (120ml/hr = 2 ml/min; 2 ml/min x 15 min = 30 ml is given in the first 15 minutes; 340 ml - 30 ml = 310 ml left to give at 240 ml/hr; 310/240 = 1.29 hour or 1 hour and 17 minutes; therefore... 15 minutes + 1 hour and 17 minutes = 1 hour and 32 minutes)