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DS - Revenue, Sales

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DS - Revenue, Sales

by karthikpandian19 » Sat Jul 21, 2012 8:38 am
The annual report of a mining company includes a circle graph showing the revenue from minerals sold during the year, in which the size of each sector of the graph is proportional to the revenue generated by sales of the mineral represented by that sector. Last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. If the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year, did cobalt sales generate more revenue this year than did iron sales?

The revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year.
Last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales.
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by niketdoshi123 » Sat Jul 21, 2012 12:21 pm
karthikpandian19 wrote:The annual report of a mining company includes a circle graph showing the revenue from minerals sold during the year, in which the size of each sector of the graph is proportional to the revenue generated by sales of the mineral represented by that sector. Last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. If the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year, did cobalt sales generate more revenue this year than did iron sales?

The revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year.
Last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales.
Statement 1:INSUFFICIENT
We don't have any information about the revenue generated last year by cobalt sales and iron sales.

Statement 2:INSUFFICIENT
We don't know by how much did iron sales this year increased or decreased than last year.

Combining both the statements

We don't know the last year's cobalt sales or iron sales.

If we consider their combined sales generated 70% of the total revenue
then, there are two possible cases

Either cobalt sales were considerably higher than the iron sales, for example cobalt sales = 60% and iron sales = 10%, in which case the revenue generated this year by cobalt sales were more than that by iron sales.

Or cobalt sales and iron sales last year were almost equal, for example cobalt sales = 36% and iron sales = 34%, in which case the revenue generated this year by cobalt sales were less than that by iron sales.

Hence INSUFFICIENT

The correct answer is E
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by eagleeye » Sat Jul 21, 2012 12:28 pm
karthikpandian19 wrote:The annual report of a mining company includes a circle graph showing the revenue from minerals sold during the year, in which the size of each sector of the graph is proportional to the revenue generated by sales of the mineral represented by that sector. Last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. If the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year, did cobalt sales generate more revenue this year than did iron sales?

The revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year.
Last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales.
In convoluted language we are simply told two things:
a) Last year revenue from cobalt sales > revenue from iron sales.
b) This year revenue from cobalt sales = 1.5* revenue from last year.

Now with this in mind, let's check the statements.

A quick look at both statements makes it seem as if each one separately isn't sufficient. So choose two contrasting test cases, each incorporating both conditions. If they work in either of the cases,
try some other approach. If it's insufficient, we know E is correct. Let's check:

Case 1:
If last year, cobalt = 34.001% and iron = 34%, iron wins (1.7 trumps 1.5)
Case 2:
If last year, cobalt = 67%, and iron = 1%, cobalt wins. (67*1.5 trumps 1*1.7).
So we see that combined statements are insufficient.

E is correct.
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by karthikpandian19 » Sat Jul 21, 2012 6:23 pm
Eageleeye & niket,

First of all i had to admit this is a tough cookie....750+ level question. But anyway here is the explanation

OA is B

The prompt describes an annual report that includes a pie chart in which each sector represents the percentage of total minerals sales generated by a certain mineral. The size, and thus the central angle, of each sector is proportional to that percentage.

We are told that last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. In other words, cobalt sales represented a larger percentage of total mineral sales than did iron sales.

Moreover, we are told that the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year. Since the central angle increases by a factor of 1.5, cobalt sales this year represent 1.5 times the percentage of total mineral sales that they did last year.

We are asked whether cobalt sales generated more revenue this year than did iron sales. If we can determine whether the percentage of revenue from cobalt sales was greater than that from iron sales, or if we can determine whether the central angle of the sector representing cobalt was greater than that of the sector representing iron, we can answer the question.

Statement 1 alone tells us that the revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year. Notice that this is an increase in absolute terms, not necessarily in terms of iron's share of total sales. We are interested in iron sales relative to the sales of other minerals (cobalt in particular), not absolute sales. The increase in iron sales could be a significant increase relative to the sale of other minerals. Or, it could be that sales of all minerals increased by at least 70%. In that case, the percentage of revenue from mineral sales generated by iron sales might actually have decreased. Since we cannot know which scenario is accurate, Statement 1 alone is not sufficient. Eliminate answer choices A and D.

Statement 2 alone tells us that last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales. Remember that cobalt sales last year made up a larger percentage of total sales than did iron sales. So cobalt sales last year must have been more than 68% ÷ 2 = 34% of the total revenue from minerals sales.

Since cobalt sales this year represent 1.5 times the percentage that they did last year, cobalt sales this year must be more than 1.5 × 34%-that is, more than 51%-of total sales. That means that even if iron were the only other mineral sold this year, iron sales must be less than 49%, since the total of the percentages of all minerals sales is 100%. Cobalt sales this year must have generated more revenue than iron sales. Statement 2 alone is sufficient.

Answer choice B is correct.
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Karthik
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by karthikpandian19 » Sat Jul 21, 2012 6:24 pm
Let me know your thoughts on this explanation
niketdoshi123 wrote:
karthikpandian19 wrote:The annual report of a mining company includes a circle graph showing the revenue from minerals sold during the year, in which the size of each sector of the graph is proportional to the revenue generated by sales of the mineral represented by that sector. Last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. If the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year, did cobalt sales generate more revenue this year than did iron sales?

The revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year.
Last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales.
Statement 1:INSUFFICIENT
We don't have any information about the revenue generated last year by cobalt sales and iron sales.

Statement 2:INSUFFICIENT
We don't know by how much did iron sales this year increased or decreased than last year.

Combining both the statements

We don't know the last year's cobalt sales or iron sales.

If we consider their combined sales generated 70% of the total revenue
then, there are two possible cases

Either cobalt sales were considerably higher than the iron sales, for example cobalt sales = 60% and iron sales = 10%, in which case the revenue generated this year by cobalt sales were more than that by iron sales.

Or cobalt sales and iron sales last year were almost equal, for example cobalt sales = 36% and iron sales = 34%, in which case the revenue generated this year by cobalt sales were less than that by iron sales.

Hence INSUFFICIENT

The correct answer is E
Regards,
Karthik
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by karthikpandian19 » Sat Jul 21, 2012 6:24 pm
Let me know your thoughts on this explanation
eagleeye wrote:
karthikpandian19 wrote:The annual report of a mining company includes a circle graph showing the revenue from minerals sold during the year, in which the size of each sector of the graph is proportional to the revenue generated by sales of the mineral represented by that sector. Last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. If the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year, did cobalt sales generate more revenue this year than did iron sales?

The revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year.
Last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales.
In convoluted language we are simply told two things:
a) Last year revenue from cobalt sales > revenue from iron sales.
b) This year revenue from cobalt sales = 1.5* revenue from last year.

Now with this in mind, let's check the statements.

A quick look at both statements makes it seem as if each one separately isn't sufficient. So choose two contrasting test cases, each incorporating both conditions. If they work in either of the cases,
try some other approach. If it's insufficient, we know E is correct. Let's check:

Case 1:
If last year, cobalt = 34.001% and iron = 34%, iron wins (1.7 trumps 1.5)
Case 2:
If last year, cobalt = 67%, and iron = 1%, cobalt wins. (67*1.5 trumps 1*1.7).
So we see that combined statements are insufficient.

E is correct.
Regards,
Karthik
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by eagleeye » Sat Jul 21, 2012 6:36 pm
karthikpandian19 wrote:Let me know your thoughts on this explanation
eagleeye wrote:
karthikpandian19 wrote:The annual report of a mining company includes a circle graph showing the revenue from minerals sold during the year, in which the size of each sector of the graph is proportional to the revenue generated by sales of the mineral represented by that sector. Last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. If the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year, did cobalt sales generate more revenue this year than did iron sales?

The revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year.
Last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales.
In convoluted language we are simply told two things:
a) Last year revenue from cobalt sales > revenue from iron sales.
b) This year revenue from cobalt sales = 1.5* revenue from last year.

Now with this in mind, let's check the statements.

A quick look at both statements makes it seem as if each one separately isn't sufficient. So choose two contrasting test cases, each incorporating both conditions. If they work in either of the cases,
try some other approach. If it's insufficient, we know E is correct. Let's check:

Case 1:
If last year, cobalt = 34.001% and iron = 34%, iron wins (1.7 trumps 1.5)
Case 2:
If last year, cobalt = 67%, and iron = 1%, cobalt wins. (67*1.5 trumps 1*1.7).
So we see that combined statements are insufficient.

E is correct.
Hi Karthik:

I agree with the OE after reading it. B is correct. I misinterpreted the statement as only saying new revenue = old one * 1.5. That was my answers downfall.
The OA and OE are accurate.
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by niketdoshi123 » Sat Jul 21, 2012 9:37 pm
Good question and nice explanation Karthik.. Will keep it in mind to check this possibility in future...
Thanks
Niket
karthikpandian19 wrote:Let me know your thoughts on this explanation
niketdoshi123 wrote:
karthikpandian19 wrote:The annual report of a mining company includes a circle graph showing the revenue from minerals sold during the year, in which the size of each sector of the graph is proportional to the revenue generated by sales of the mineral represented by that sector. Last year, the central angle of the sector representing cobalt sales was larger than the central angle of the sector representing iron sales. If the measure of the central angle of the sector representing cobalt sales is 50% greater this year than it was last year, did cobalt sales generate more revenue this year than did iron sales?

The revenue from the sale of iron this year is 70% greater than the revenue from the sale of iron last year.
Last year, the combined sales of cobalt and iron generated more than 68% of the company's total revenue from minerals sales.
Statement 1:INSUFFICIENT
We don't have any information about the revenue generated last year by cobalt sales and iron sales.

Statement 2:INSUFFICIENT
We don't know by how much did iron sales this year increased or decreased than last year.

Combining both the statements

We don't know the last year's cobalt sales or iron sales.

If we consider their combined sales generated 70% of the total revenue
then, there are two possible cases

Either cobalt sales were considerably higher than the iron sales, for example cobalt sales = 60% and iron sales = 10%, in which case the revenue generated this year by cobalt sales were more than that by iron sales.

Or cobalt sales and iron sales last year were almost equal, for example cobalt sales = 36% and iron sales = 34%, in which case the revenue generated this year by cobalt sales were less than that by iron sales.

Hence INSUFFICIENT

The correct answer is E
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