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OG16 - DS 160

Expert replies
Source: — Data Sufficiency |

by GMATGuruNY » Tue May 24, 2016 8:09 am
What amount did Jean earn from the commission on her sales in the first half of 1988 ?

(1) In 1988 Jean's commission was 5 percent of the total amount of her sales.
(2) The amount of Jean's sales in the second half of 1988 averaged $10,000 per month more than in the first half
Statement 1:
If Jean's total sales = $100, then her commission = 5% of 100 = $5.
If Jean's total sales = $1000, then her commission = 5% of 1000 = $50.
Since her commission can be different values, INSUFFICIENT.

Statement 2:
Since the commission rate is unknown, INSUFFICIENT.

Statements combined:
Case 1: Sales for the first half of the year = $10000 per month, sales for the second half of the year = $20000 per month
In this case:
Total sales = (6*10000) + (6*20000) = $180,000.
Commission = 5% of 180,000 = $9,000.

Case 2: Sales for the first half of the year = $20000 per month, sales for the second half of the year = $30000 per month
In this case:
Total sales = (6*20000) + (6*30000) = $300,000.
Commission = 5% of $300,000 = $15,000.

Since the commission can be different values, INSUFFICIENT.

The correct answer is E.
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by OptimusPrep » Thu May 26, 2016 7:10 pm
amina.shaikh309 wrote:Image
Required: How much did Jean earn in commission in first half of 1988

Statement 1: In 1988 Jean's commission was 5 percent of the total amount of her sales
Since we do not know the total sales, we cannot find the commission.
INSUFFICIENT

Statement 2: The amount of Jean's sales in the second half of 1988 averaged $10,000 per month more than in the first half
Nothing discussed about the commission percentage.
Clearly INSUFFICIENT

Combining both statements:
We just know the difference between the sales of both halves, but not the absolute values.
The commission will depend on the absolute values.
Still INSUFFICIENT

Correct Option: E
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by nchaswal » Sat May 28, 2016 5:48 am
Amina

I have a question for you. How long did it take you to solve this ? And did you solve this correctly ?

This is hardly a 1 Min question and just like I explained in one of the problems you posted, if some key principles are etched in your mind you do not have to spend much time on a problem. It is just like knowing multiplication table of 5. You can never forget it and it is always at ur finger tips that any multiple of 5 can either have last digit as 5 or 0.

Statement 1:INSUFFICIENT ( 10 secs)

Again as the question is EXACT value Q, only % will not give you answer.

Statement 2: INSUFFICIENT (15 secs)

The variable X is first half sales. This statement gives no info about X.

COMBINE: INSUFFICIENT (20-30 secs)

You have the % but you still do not have X so no point thinking further.

Answer : E

You saved almost more than 1 min by keeping some simple rules at tips.

Cheers
It is GMAT. So what?
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