Math questions on the PTCB practice exams
Ketoconazole 2% in polythylene glycol is commonly used for ringworm treatment. To
compound a pint of this solution, the pharmacy technician must weigh what amount of
Ketoconazole?
a) 4.8 g
b) 480 g
c) 9.6 g
d) 960 g
1 pint = ? oz
1 oz = ? g Ans: 1 pint = 16 oz
1 oz = 30 g
1. Do a proportion to calculate how many grams in a pint.
1 oz/30 g = 16 oz/x g
x = 480 g
2. Convert 2% to a decimal and calculate 2% of 480g = x g
.02 x 480g = 9.6 g
Answer: c) 9.6g
If the concentration of a stock of medication vial is 0.25g/ml, what volume of stock solution is
required to deliver a dose of 800mg?
a) 0.32ml
b) 3.2 ml
c) 32 ml
d) 320 ml
1 g = ? mg Ans: 1 g = 1000 mg
1. Do a proportion to calculate how many mg is equivalent to .25g/ml.
1 g/1000 mg = .25g / x mg
x = 250 mg
2. Do a proportion to calculate how many ml is equivalent to 800 mg.
250mg/1 ml = 800 mg/x ml
x = 3.2 ml
Answer: b) 3.2 ml
A 40 ml stock vial of Ranitidine contains a 25mg/ml solution. How many milliliters must be
withdrawn for a patient who requires 50 mg Ranitidine IV? Ans: 40 ml - info not necessary
,Do a proportion to calculate how many ml is equivalent to 50mg
25mg/1ml = 50 mg/x ml
x = 2 ml
Answer: b) 2 ml
The maximum amount per transaction of pseudoephedrine is 3.6 g. What is the maximal number
of 30 mg tablets allowable in a single transaction?
a) 12
b) 60
c) 108
d) 120
1 g = ? mg Ans: 1 g = 1000 mg
Do a proportion to calculate how many mg in a transaction.
1 g/1000 mg = 3.6g/x mg
x = 3600 mg
Divide 3600/30 mg = 120
Answer: d) 120 maximum number per transaction
Lidocaine is supplied in packets of 20 vials. Each of 24 nursing stations must have 12 vials.
What is the total number of packages needed?
a) 10
b) 14
c) 15
d) 40 Ans: Multiply 24 x 12 = 288
Divide 288/20 = 14.4
Round up 14.4 to 15 packages
Answer c) 15
What is the percentage concentration of a 400mg/500ml solution?
a) .008%
b) .08%
c) .8%
d) 8%
formula w/v% = ? x ? Ans: w/v% = g/ml x 100
1 g = 1000 mg
Convert 400 mg to g using proportion.
, 1g/1000mg = xg/400mg
x = .4g
Calculate formula
.4g/500ml x 100 = .08%
Answer: b) .08%
Using a standard heparin solution (25,000 units/500ml D5W), how many milliliters per hour
should the infusion rate be to achieve a dose of 1100 units/hr.
a) 2.2
b) 11
c) 22
d) 44
formula: ml/hr = ? x ? Ans: ml/hr = dose/hr x volume of IV/concentration of IV
Calculate formula
1100 units / 1 hr x 500 ml / 25000 units
(units cancel, left with ml/hr)
= 22 ml/hr
Answer: c) 22
How many milliliters of Cephalexin suspension 250mg/5ml would provide a patient with 2
teaspoonfuls four times a day for seven days?
a) 140
b) 250
c) 280
d) 300
1 tsp = ? ml Ans: 1 tsp = 5 ml
not necessary info: 250mg/5ml
2tsp = 10 ml x 4 times a day = 40ml per day x 7 days = 280 ml for full course of treatment.
Answer: c) 280
A 55 lb child is to receive Heparin sodium by IV infusion in a dose of 50 units/kg of body weight
every 4 hours. How many milliliters of Heparin sodium injection containing 5,000 units/ml will
be administered for each dose?
a) 0.15
b) 0.25
c) 1.5
d) 2.5
Ketoconazole 2% in polythylene glycol is commonly used for ringworm treatment. To
compound a pint of this solution, the pharmacy technician must weigh what amount of
Ketoconazole?
a) 4.8 g
b) 480 g
c) 9.6 g
d) 960 g
1 pint = ? oz
1 oz = ? g Ans: 1 pint = 16 oz
1 oz = 30 g
1. Do a proportion to calculate how many grams in a pint.
1 oz/30 g = 16 oz/x g
x = 480 g
2. Convert 2% to a decimal and calculate 2% of 480g = x g
.02 x 480g = 9.6 g
Answer: c) 9.6g
If the concentration of a stock of medication vial is 0.25g/ml, what volume of stock solution is
required to deliver a dose of 800mg?
a) 0.32ml
b) 3.2 ml
c) 32 ml
d) 320 ml
1 g = ? mg Ans: 1 g = 1000 mg
1. Do a proportion to calculate how many mg is equivalent to .25g/ml.
1 g/1000 mg = .25g / x mg
x = 250 mg
2. Do a proportion to calculate how many ml is equivalent to 800 mg.
250mg/1 ml = 800 mg/x ml
x = 3.2 ml
Answer: b) 3.2 ml
A 40 ml stock vial of Ranitidine contains a 25mg/ml solution. How many milliliters must be
withdrawn for a patient who requires 50 mg Ranitidine IV? Ans: 40 ml - info not necessary
,Do a proportion to calculate how many ml is equivalent to 50mg
25mg/1ml = 50 mg/x ml
x = 2 ml
Answer: b) 2 ml
The maximum amount per transaction of pseudoephedrine is 3.6 g. What is the maximal number
of 30 mg tablets allowable in a single transaction?
a) 12
b) 60
c) 108
d) 120
1 g = ? mg Ans: 1 g = 1000 mg
Do a proportion to calculate how many mg in a transaction.
1 g/1000 mg = 3.6g/x mg
x = 3600 mg
Divide 3600/30 mg = 120
Answer: d) 120 maximum number per transaction
Lidocaine is supplied in packets of 20 vials. Each of 24 nursing stations must have 12 vials.
What is the total number of packages needed?
a) 10
b) 14
c) 15
d) 40 Ans: Multiply 24 x 12 = 288
Divide 288/20 = 14.4
Round up 14.4 to 15 packages
Answer c) 15
What is the percentage concentration of a 400mg/500ml solution?
a) .008%
b) .08%
c) .8%
d) 8%
formula w/v% = ? x ? Ans: w/v% = g/ml x 100
1 g = 1000 mg
Convert 400 mg to g using proportion.
, 1g/1000mg = xg/400mg
x = .4g
Calculate formula
.4g/500ml x 100 = .08%
Answer: b) .08%
Using a standard heparin solution (25,000 units/500ml D5W), how many milliliters per hour
should the infusion rate be to achieve a dose of 1100 units/hr.
a) 2.2
b) 11
c) 22
d) 44
formula: ml/hr = ? x ? Ans: ml/hr = dose/hr x volume of IV/concentration of IV
Calculate formula
1100 units / 1 hr x 500 ml / 25000 units
(units cancel, left with ml/hr)
= 22 ml/hr
Answer: c) 22
How many milliliters of Cephalexin suspension 250mg/5ml would provide a patient with 2
teaspoonfuls four times a day for seven days?
a) 140
b) 250
c) 280
d) 300
1 tsp = ? ml Ans: 1 tsp = 5 ml
not necessary info: 250mg/5ml
2tsp = 10 ml x 4 times a day = 40ml per day x 7 days = 280 ml for full course of treatment.
Answer: c) 280
A 55 lb child is to receive Heparin sodium by IV infusion in a dose of 50 units/kg of body weight
every 4 hours. How many milliliters of Heparin sodium injection containing 5,000 units/ml will
be administered for each dose?
a) 0.15
b) 0.25
c) 1.5
d) 2.5
