If it is assumed that 60 percent of those who receive a questionnaire

Question

If it is assumed that 60 percent of those who receive a questionnaire by mail will respond and 300 responses are needed, what is the minimum number of questionnaires that should be mailed?

(A) 400
(B) 420
(C) 480
(D) 500
(E) 600

Kudos for a correct  solution .

BrentGMATPrepNow · Accepted Answer

60 percent of those who receive a questionnaire by mail will respond   
Rewrite as:  60 percent of receivers = responders 
We want  300  responders, so rewrite as:  60 percent of receivers =  300  
60% of what =  300 ?

Option #1) Check answer choices 
A) 400
60% of 400 = 240 (nope, we want  300 )
.
.
.
D) 500
60% of 500 =  300 ...works!!

Or option #2) algebra 
60% of x =  300 
0.6x = 300
x = 300/0.6
= 500
=  D

Or... 
60% of x =  300 
0.6x = 300
(3/5)x = 300
x = (5/3)300
= 500
= D

Cheers,
Brent

asethi · Answer

given: 60% will respond, so 300 is the 60% of the x questionnaires sent.
then x=300*100/60=500

Ans: D

v12345 · Answer

Minimum no of mail to be sent for getting 300 responses at 60%

= 300/0.6 = 500 Ans

Option D

Mun20 · Answer

Let c be the number of questionnaires mailed 
We need 300 responses 
So 60% of c should be equal to 300
60/100*c=300
C=30000/60
C=500

camlan1990 · Answer

300 *100/60 = 500

Ans: D

kamranko · Answer

60%*x=300 ===> 60/100 * x= 300

300*100 / 60 = x

x=500

D

Divyadisha · Answer

If 300 is 60%, then 100% would be= 300*100/60= 500

D is the answer

nkmungila · Answer

60/100 = 300
then 30000/60 = 500
Hence Answer is 500

JeffTargetTestPrep · Answer

If we let x = the number of questionnaires that should be mailed, then x must satisfy 0.6x = 300. Then, x = 300/0.6 = 500.

Answer: D

FANewJersey · Answer

One of the most overlooked ways to solve such questions is "Guess and Check". If we look at this question, we can see that the easiest option to attack is (D) 500:

500 is half of 1000. So 60% of 1000 = 600, and hence 600% of 500 (which is half of 1000) will be 300 ----> our answer (D).

albertocalvou87 · Answer

Consider X as the number of questionnaires mailed. 300 is the minimum of answers we need. So, let's fix our equation with 300 as the total needed. Therefore, the total number of questionnaires mailed multiplied by 60 % (minimum of answers assumed) should equal our needed number (300).

X(60/100)=300

- You can take 0s out and add them again at the end to make the calculations easier-

X(6/10)=30
X(6)=30*10
X=300/6
X=50

- Adding the 0 again-

X=500

Answer: D
hope this helps!

Posted from my mobile device

MartyTargetTestPrep · Answer

Alternate Approach

If it is assumed that 60 percent of those who receive a questionnaire by mail will respond and 300 responses are needed, what is the minimum number of questionnaires that should be mailed?

A good tool to have in your quant toolkit is facility with percentage to fraction conversion for round number percentages.

You can easily memorize 5% = 1/20, 10% = 1/10, and 20% = 1/5, and once you have those three memorized, the rest follow.
 
For instance:

10% = 1/10

20% = 1/5

50% = 5/10 = 1/2

60% = 3/5

95% = 19/20

To answer this question, we can use percentage to fraction conversion in the following extremely simple and fast way.

300 = 60% of the total we need = 3/5 of the total

300 = 3/5 --> 100 = 1/5

The total is therefore 5 x 100 = 500.

The correct answer is D.

gsmina · Answer

I simply solved it by % rule of:

Part/whole = x/100

300/x = 60/100

x = 500.

Answer E.

akadiyan · Answer

If it is assumed that 60 percent of those who receive a questionnaire by mail will respond and 300 responses are needed, what is the minimum number of questionnaires that should be mailed?

300 is 60%

So 100% is  (\frac{300}{60}*100)  = 500

Ans   D

Abhishek009 · Answer

\frac{300}{60}*100 = 500 , Answer will be (D)

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

If it is assumed that 60 percent of those who receive a questionnaire

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Problem Solving (PS) Questions

If it is assumed that 60 percent of those who receive a questionnaire

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards