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Pie chart

by talaangoshtari » Thu May 07, 2015 8:39 pm
Royalty on the book is less than the printing cost by:

A. 5%
B. 33 1/5%
C. 20%
D. 25%
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piechart1.png

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by [email protected] » Fri May 08, 2015 9:01 am
Hi talaangoshtari,

This question is poorly-phrased, but the "intent" of it is probably to test you on your knowledge of "Percentage Change" (which is a specific formula that you WILL need to know for Test Day).

Percentage Change = (difference)/(original) = (New - Old)/(Old)

From the pie chart, we can see that:
Royalty = 15% of the total cost
Printing = 20% of the total cost

Comparing those two percents (and using the percentage change formula) gives us....

(15 - 20)/(20) = -5/20 = -1/4 = 25% less

Final Answer: D

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by talaangoshtari » Fri May 08, 2015 9:10 am
Hi, thank you for your reply. Would you please explain why A is wrong?

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by [email protected] » Fri May 08, 2015 3:11 pm
Hi talaangoshtari,

Based on the information in the pie chart, we do NOT know the exact price of any of the pieces - we only know the PERCENT of the TOTAL EXPENDITURES that each piece represents. Since we don't know the total expenditures, we have no way of calculating "how much less" one piece is compared to another (this is why I mentioned in my prior post that the question was 'poorly-phrased').

For example,

IF....the total expenditures = $100...
Printing = $20
Royalty = $15
Royalty is 20-15 = $5 less

IF....the total expenditures = $200...
Printing = $40
Royalty = $30
Royalty is 40-30 = $10 less

As the total expenditures change, the 'absolute' difference in Printing and Royalty changes.

If the question had asked "what is the difference in the percent of expenses devoted to Printing and the percent of expenses devoted to Royalty?", then the answer would be 5%, but that's NOT how this question was written.

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