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Manager
Joined: 15 Aug 2005
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I am a little unsure about the rule for which denominator to [#permalink]
13 Dec 2005, 07:43
I am a little unsure about the rule for which denominator to use in some % problems. Try the following question for example and let me know if you have the rule:
At Company X senior sales representatives visit the home office once every 30 days, and junior sales representatives visit the home office once every 20 days. The number of visits that a junior sales representative makes in a 2-year period is approximately what percent greater than the number of visits that a senior representative makes in the same period?
A. 10%
B. 25%
C. 33%
D. 50%
E. 67%
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Current Student
Joined: 29 Jan 2005
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2 years is approximately 720 days (24*30).
For senior: 720/30=24
For junior: 720/20=36
36/24=1.5
Therefore 50% more.
(D)
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Manager
Joined: 20 Nov 2005
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Location: Indianapolis, IN
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I get D - Approximately 50%
Set up as follows:
Junior Rep visits the office 1/20 days.
Senior rep visits the office 1/30 days
(1 visit/20 days)*(365 days/year)*(2 years)= ~36 days visiting the office in a 2 year time span.
(1 visit/30 days)*(365 days/year)*(2 years)= ~24 days visiting the office in a 2 year time span.
36-24 = 12
12/24(100) = 50%
If you notice, when I set up the equation to get the number of days each rep visited in the two years, the "labels" canceled each other out. I remember learning about this technique in science class to make conversions (for example from hours to minutes to seconds). Essentially, you want the solution you're looking for (in this case the # of visits), to end up on top and alone. You'll notice that there is a "day" label on top and bottom - they cancel each other out. Also, you'll notice there's a "years" label on top and bottom as well, and they cancel each other out. This leaves "visits" alone and on top.
I hope that makes sense...and I hope that's what you were looking for...
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Senior Manager
Joined: 05 Oct 2005
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If the question states "x is what percent greater/smaller than y?", y will always be the denominator. (x-y)/y
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Senior Manager
Joined: 03 Nov 2005
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Location: Chicago, IL
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Juinor repr.=360/20=18
Sen repr.=360/30=12
18/12==3/2= 1 1/2 or 50%
It does't matter what period you are considering, this ratio 3/2 will always stay the same.
D stands
_________________
Hard work is the main determinant of success
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Director
Joined: 27 Jun 2005
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yb wrote: If the question states "x is what percent greater/smaller than y?", y will always be the denominator. (x-y)/y
C
I agree with you "yb" ....it should be 12/36*100= 33%
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CEO
Joined: 20 Nov 2005
Posts: 2934
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008
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No need to calculate by years. The ratio of visiting frequency of S to J is 2:3.How much percentage 3 is greater than 2. Simply and exactly (no approximate) 50%. It will be 33% if asked how much percentage lesser is Senior's visit form Junior's.
_________________
SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008
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