# Pharmacy Calculation Questions and Answers (Part-1)

#### Q1. How many grams of Dextrose are required to prepare 5% of 500 cc solution?

Answer: (500×5)/100 = 25 grams of dextrose.

#### Q2. How much Lidocaine is required to prepare 1 : 1000, 30 cc of solution of Lidocaine?

Answer: (30×1)/1000 = 0.03 g = 30 mg

#### Q3. How much Atropine is required to dispense 1 quart of 1 in 100 solution?

Answer: 1 in 100solution is interpreted as 1 gm of drug in 100 cc of solution. We want to find out how much atropine is required to dispense 1 quart (960 cc) of 1 in 100 solution, therefore:

(960 x 1)/100 = 9.6 gm  = 9600 mg atropine is required.

#### Q4. How many milligrams are equal to 1/150 gr of Nitroglycerine?

Answer: 1 grain is equal to 65 milligrams, therefore 1/150 grains are equal to:

= (1 x 65)/150 = 0.43 milligrams.

#### Q6. If 1 teaspoonful of Thioridazine concentrated solution(30mg/cc) is diluted up to the 480cc mark with plain water, what is the strength of drug in mg/ml in the final solution?

Answer: 1 teaspoonful (5 cc) of Thioridazine solution (30mg/cc) contains 150 mg of drug. This solution is diluted up to a mark of 480 cc therefore:

150/480 = 0.31 mg/ml

#### Q7. How many grams of Heparin are required to prepare 1 quart of 0.45% solution?

Answer: We want to prepare 1 quart (960 cc) of 0.45% heparin solution, therefore we can say:

(960 x 0.45)/100 = 4.32 gm.

#### Q8. Erythromycin 2% 60 cc topical solution contains:

Answer: (60 x 2)/100 = 1.2 gm of erythromycin.

#### Q9. If 60mg of elementary iron are present in 325 mg of ferrous sulfate, what is the % of elementary iron?

Answer: (100 x 60)/325 = 18.46%

#### Q10. If a prescription reads “100 mcg cyanocobalamin i.m. every week”, how many ampules of 1000 mcg/cc are required to fill a month supply?

Answer: Patient is taking 100 mcg of the drug i.m. every week, therefore:

= 100/1000 = 0.1 cc of drug = 1 ampule every week.

#### Q11. How much Clobetasole is present in 60 gm of 0.5% ointment?

Answer: (60 x 0.5)/100 = 0.3 gm of clobetasole.

#### Q12. Find out the volume of 5 lb of glycerin. [density= 1.25 gm/ml]

Answer: We know, Volume = weight/density; therefore:

(5 x 454)/1.25 (where, 1 lb = 454 gm) = 1816 ml glycerin.

#### Q13. Calculate the weight of 500 cc of acid. [density of acid = 2.5 gm/ml]

= 2.5 x 500

= 1250 gm of acid.

#### Q14. How many 500 mg tablets of erythromycin are required to prepare 240 cc of 2% solution of erythromycin?

Answer: 240 cc 2% Erythromycin solution contains:

= (240 x 2)/100 = 4.8 gm of Erythromycin

The number of 500 mg tablets of Erythromycin:

= 4800/500 = 9.6 = 10 tablets.

#### Q15. Find out the weight in gm of 500 cc glycerine. [Specific gravity= 1.25 gm/ml]

Answer: Weight in grams = no of ml x sp gr

= 500 cc x 1.25 gm/cc

= 625 gm