A doctor prescribed 18 cubic centimeters of a certain drug to a patien

Question

A doctor prescribed 18 cubic centimeters of a certain drug to a patient whose body weight was 120 pounds. If the typical dosage is 2 cubic centimeters per 15 pounds of the body weight, by what percent was the prescribed dosage greater than the typical dosage?

A) 8%
B) 9%
C) 11%
D) 12.5%
E) 14.8%

A) 8% 
B) 9% 
C) 11% 
D) 12.5%
E) 14.8%

BrentGMATPrepNow · Accepted Answer

We can use  equivalent ratios  to determine what the dosage SHOULD have been.
We'll use the ratio of  drug dosage (in cubic centimeters) / body weight (in pounds)

Let  x  = the dosage (in cubic centimeters) the patient SHOULD have received

We get:  2 / 15  =  x / 120 
Cross multiply to get: 15x = (2)(120)
Simplify: 15x = 240
Solve:  x = 16 
So, the patient SHOULD have received a dosage of 16 cubic centimeters
Instead, the patient was prescribed a dosage of 18 cubic centimeters

Percent increase = 100(new - original)/original
= 100(18 - 16)/16
= 200/16 
= 12.5

Answer: D

RELATED VIDEO
 https://www.youtube.com/watch?v=Yegch7sv6MY

ScottTargetTestPrep · Answer

The typical dosage is 2 cubic centimeters (cc) per 15 pounds of body weight. We can set up a proportion to determine what the typical number of cc of the drug would be for a patient with a body weight of 120 pounds:
 
2/15 = x/120
 
240 = 15x
 
240/15 = x
 
16 = x
 
Thus, the typical dose for this 120-pound patient is 16 cc. To determine the percent greater than this dose that 18 cc would be, we can use the percent change formula.
 
(Doctor dose – typical dose)/typical dose x 100%
 
(18 – 16)/16 x 100% = 2/16 x 100% = 0.125 x 100% = 12.5%

Answer: D

CounterSniper · Answer

typical dosage = 2 cubic centimetres per 15 pounds of the body weight
or,
1200/75= 16 cubic centimetres for a body weight of 120 pounds
doctor prescribed 18 cubic centimetres
greater by (2/16)= 12.5%

adiagr · Answer

Typical dosage is Dose : weight :: 2: 15.

Now if weight is 120 (Multiplying factor is 8: (120/15)) then typical dosage would be 2 *8 = 16 cc.

Dosage = 18 cc. Dosage is greater by 2 cc.

% disage is greater: (2 / 16)*100 = 12.5 %

D is the answer.

Skywalker18 · Answer

Typical dosage per 15 pound of the body weight = 2 c.c
Typical dosage per 120 pound of the body weight = 2 *(120/15) 
= 2 * 8 
= 16 c.c 
Dosage prescribed by doctor for 120 pound patient = 18 c.c
% prescribed dosage greater than the typical dosage = (18-16/16) *100%
=(2/16) *100%
= 12.5%
Answer D

thefibonacci · Answer

typical dosage: for 15p -- 2 cc
=> for 1p -- 2/15 cc 
=> for 120p -- (2/15)*120 = 16cc 
so, (18-16)/16 % = 12.5% -- option d.

Divyadisha · Answer

Ideal prescription is 2 cubic centimeters for 15 pounds of body weight.

for 120 pounds, it will be= 2*120/15= 16 cubic centimeters

Prescribed dosage= 18 cubic centimeters

% increase= 18-16/16*100= 12.5%

D is the answer

EMPOWERgmatRichC · Answer

Hi All,

This question is essentially about working through the necessary arithmetic. Thankfully, the math itself isn't that tough, but you do have to stay organized to make sure that you're setting up the proper calculations.

We're told that a typical dose of a drug is 2 cm^3 per 15 pounds. With a 120 pound person, there are 8 15-pound "sets", so the typical dose would be 8(2 cm^3) = 16 cm^3. Since the doctor prescribed 18 cm^3 of the drug, the dose was clearly larger than the typical dose. The question asks by what percent greater was that dose.

Since 18 is "2 more" than 16, we can know that the prescribed dose was 2/16 = 1/8 = 12.5% greater than it typically would be.

Final Answer:  D

GMAT assassins aren't born, they're made, 
Rich

satheshshiva · Answer

Recommended dose, 2cc/15 lbs Doctor did, 18cc/120 lbs bad doctor

Since we know 2 will nicely go over 18, 18/2 = 9 At 9 times, 2cc will be suitable for 9*15 = 135 lbs. This doctor has given a dosage for someone who is 15 lbs lesser So, (difference / original) * 100 = Percentage increase (15/120) * 100 = 12.5% increase in dosage

Pritishd · Answer

Prescribed Ratio = 18/120 = 3/20
Typical Ratio = 2/15
% Change (Greater) = (Prescribed Ratio - Typical Ratio) / (Typical Ratio) = (3/20-2/15) / (2/15) = (1/8)
Converting to %:
1/8 is 0.125 = 0.125*100 = 12.5%

fskilnik · Answer

Perfect opportunity for  UNITS CONTROL , one of the most powerful tools carefully explained in our course!

{m{atypical}}\,\,\left( {120\,\,{m{pounds}}} ight)\,\,\,:\,\,\,18\,{m{c}}{{m{m}}^3}

{m{typical}}\,\,\,{m{:}}\,\,\,120\,{m{pounds}}\,\, \cdot \,\,\left( {{{2\,{m{c}}{{m{m}}^3}} \over {15\,{m{pounds}}}}} ight)\,\,\, = \,\,\,16\,\,{m{c}}{{m{m}}^{m{3}}}

16\mathop 	o \limits^{?\, = \,\Delta \% } 18\,\,\,\,\left

{m{?}}\,\, = \,\,\Delta \% \,\, = \,\,{{18 - 16} \over {16}}\,\,\, = \,\,\,{1 \over 8} \cdot 100\% \,\,\, = \,\,\,12.5\%

The correct answer is therefore (D).

We follow the notations and rationale taught in the  GMATH  method.

Regards,
Fabio.

GMATinsight · Answer

Answer: Option D

Video solution by  GMATinsight

https://www.youtube.com/watch?v=EHXPLfv2HnE

avigutman · Answer

Video solution from Quant Reasoning: Subscribe for more: https://www.youtube.com/QuantReasoning? ... irmation=1 https://www.youtube.com/watch?v=UI86sX0sejY

tarunrathi999 · Answer

2 cubic centimeters per 15 pounds of the body weight

2cc = 15 p

Multiply both sides by 8

2*8 cc = 15*8 p

16cc = 120 p

So we know it's 2 cc extra

Final answer = (Change/Original)* 100 = (2/16)*100 = 12.5%

Other alternative option is

2 cc= 15 p

1cc = 7.5 p
(x)cc = 120 p

x = 120/7.5 = 16 cc

Leon685 · Answer

Just did some dumb math.

Normal: 2 per 15 or 16 per 120
Prescribed: 18 per 120

=    +

--> 2 divided by 16 is the relevant part since it shows us "what percent greater" the prescribed dosage is.
   =    = 0.125 = 12.5 %

A doctor prescribed 18 cubic centimeters of a certain drug to a patien

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A doctor prescribed 18 cubic centimeters of a certain drug to a patien

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