Company S produces two kinds of stereos: basic and deluxe.

Question

Company S produces two kinds of stereos: basic and deluxe. Of the stereos produced by Company S last month, 2/3 were basic and the rest were deluxe. If it takes 7/5 as many hours to produce a deluxe stereo as it does to produce a basic stereo, then the number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos?
A. 7/17
B. 14/31
C. 7/15
D. 17/35
E. 1/2

I'm not getting how to solve it?
Please help.
Thanks a lot in advance.

A. 7/17 
B. 14/31 
C. 7/15 
D. 17/35 
E. 1/2

KarishmaB · Accepted Answer

The easiest way would be to assume values:
2/3 were basic, 1/3 were deluxe.
So assume 2 basic and 1 deluxe were produced.
If 5 hrs are needed to make a basic one, 7 hrs are needed to make a deluxe stereo.
Total hrs needed = 2 x 5 + 1 x 7 = 17 out of which 7 were used for deluxe stereo.
So 7/17 is the fraction of time spent in making the deluxe stereo.

Since everything is in fraction terms, i.e. one related to the other, it is pretty easy to assume values and solve. Same should be done when everything is in percentage terms.

Bunuel · Answer

udaymathapati please do check the questions when posting. Correct question is as follows:

Company S produces two kinds of stereos: basic and deluxe. Of the stereos produced by Company S last month, 2/3 were basic and the rest were deluxe. If it takes 7/5 as many hours to produce a deluxe stereo as it does to produce a basic stereo, then the number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos?
A. 7/17
B. 14/31
C. 7/15
D. 17/35
E. 1/2

I'm not getting how to solve it?
Please help.
Thanks a lot in advance.

A. 7/17 
B. 14/31 
C. 7/15 
D. 17/35 
E. 1/2

# of basic stereos was 2/3 of total and # of deluxe stereos was 1/3 of total, let's assume total = 15, then Basic = 10 and Deluxe = 5.

Now, if time needed to produce one Basic stereo is 1 unit than time needed to produce one Deluxe stereo would be 7/5 units. Total time for Basic would be 10*1 = 10 and total time for Deluxe would be 5*7/5 = 7 --> total time for both of them would be 10 + 7 = 17 --> deluxe/total = 7/17.

Answer: A.

sandeep800 · Answer

OHHHHHHHHHH Goshhhhhhhhhhhhhhhhhh Thanx a lot bunuel u were a savior..I would have spent my whole night solving this question i tried every possible way to find out solution...trust me the only last thing i was trying to find out how can i make this question correct from the answer choices..

( where did u find this question BTW?

dimitri92 · Answer

we have the following ratios:
basic (b) : deluxe (d)
2 units : 1 unit
5 hrs : 7 hrs

total time taken to produce basic units = 2*5= 10hrs
total time taken to produce deluxe units = 1*7= 7hrs
total time taken = 10+7= 17hrs

so, 7/17

HTH

TomB · Answer

Hai Karishma,
 
 I have a trouble in calculating the time to produce one deluxe stereo. How did you get value 7. I try to calculate in the following manner. (5+5*7/5) . I know it is wrong. Please explain. where i went wrong

KarishmaB · Answer

I have assumed values here. Let's look at the question again.

Company S produces two kinds of stereos: basic and deluxe. Of the stereos produced by Company S last month, 2/3 were basic and the rest were deluxe.

Ok so if a total of 3 stereos were produced, 2 were basic (because 2/3 are basic) and 1 was deluxe

If it takes 7/5 as many hours to produce a deluxe stereo as it does to produce a basic stereo, 
 
It takes 7/5 as many hours.. So if it takes 5 hrs to produce a basic one, a deluxe one takes 7/5 * 5 = 7 hrs. The question says 7/5 as many hours so you just multiply the hours it takes to produce a basic one with 7/5. Think of it this way - if the question said, "it takes twice as many hours as it takes to produce a basic one..." would you just multiply by 2 or would you follow your method?
 
then the number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos?

Hours taken for 2 basic stereos = 2*5
Hours taken for 1 deluxe = 1*7
Total hours = 17
Required fraction = 7/17

dave13 · Answer

Hi Bunuel

one question: what does "takes 7/5 as many hours " mean like it takes 1.4 hours to produce basic units and same time 1.4 takes to produce deluxe units ? if yes, than why multiplying 1 by 10 to find time

to find time we need to divide work by rate no ?

thanks

Bunuel · Answer

x times as many as y means x multiplied by y. For example, twice as many as y means 2y. So, if it takes 7/5 as many hours to produce a deluxe stereo as it does to produce a basic stereo, means that  if time needed to produce one Basic stereo is   1   unit than time needed to produce one Deluxe stereo would be   1*7/5=7/5   units. .

Next, if  Basic=  10   and Deluxe=  5   , then time to produce 10 Basic would be   10 * 1  =10 and time to produce 5 Deluxe would be   5 * 7/5  =7

JeffTargetTestPrep · Answer

We can let the total number of stereos = 12; thus, 8 are basic and 4 are deluxe.

We can let the number of hours to produce a basic stereo = 10, and thus it takes 7/5 x 10 = 14 hours to produce a deluxe stereo.

The number of hours to produce the deluxe stereos last month was 14 x 4 = 56 hours, and the number of hours to produce the basic stereos was 8 x 10 = 80 hours.

Thus, the time to make the deluxe stereos was 56/(56 + 80) = 56/136 = 7/17 of the total time taken to produce all stereos.

Answer: A

GMATinsight · Answer

Answer: Option A

Please check the video for the step-by-step solution.

GMATinsight's Solution

https://www.youtube.com/watch?v=2niSRUhVcVc

EgmatQuantExpert · Answer

Solution 
 
  Given  
 • Company S produces two kinds of stereos: basic and deluxe.
• Of the stereos produced by Company S last month, 2/3 were basic and the rest were deluxe.
• It takes 7/5 times as many hours to produce a deluxe stereo as it does to produce a basic stereo 
  To find  
 • The number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos 
 o Time to produce all deluxe stereos/Time to produce all stereos

Approach and Working out   
 • Let the total number of stereos produced be s.
 o Then, number of basic stereos = 2s/3 ---------- (1a) 
o And the number of deluxe stereos = remaining stereos = s/3 ---------(2a)

• Let the time taken to produce a basic studio be ‘t’. -----------(1b)
 o Then, the time to produce a deluxe stereo = 7t/5 -----------(2b)

• Total time to produce:
 o All the basic stereos = (2s/3) * t.  
o All the deluxe stereos = (s/3) * (7t/5).   -------------(3)
o All the stereos =   +   = 17st/15 ----------(4)

Finally, the required fraction = (7st/15)/(17st/15) = 7/17

Correct Answer: Option A

srikanth9989 · Answer

Let me know if this is a better approach!
 
Let
200 basic stereos - 1 hour to make - 200 hours
100 deluxe stereos - 1.4 hours to make - 140 hours

Total 340 hours.

140/340 hours = 7/17 hours

Company S produces two kinds of stereos: basic and deluxe.

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Company S produces two kinds of stereos: basic and deluxe.

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