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If a certain toy store's revenue in November was 2/5 of its [#permalink]
 25 Jun 2012, 02:36
Question Stats:
62% (02:17) correct
37% (01:06) wrong based on 5 sessions
The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions ProjectIf a certain toy store's revenue in November was 2/5 of its revenue in December and its revenue in January was 1/4 of its revenue in November, then the store's revenue in December was how many times the average (arithmetic mean) of its revenues in November and January? (A) 1/4 (B) 1/2 (C) 2/3 (D) 2 (E) 4 Diagnostic Test
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
25 Jun 2012, 02:36
SOLUTIONIf a certain toy store's revenue in November was 2/5 of its revenue in December and its revenue in January was 1/4 of its revenue in November, then the store's revenue in December was how many times the average (arithmetic mean) of its revenues in November and January?(A) 1/4 (B) 1/2 (C) 2/3 (D) 2 (E) 4 Probably, for most people it would be easier to solve such kind of questions by picking numbers. Notice that January is linked with November and November is linked with December. So, we should pick some smart number for December's revenue. Since the denominators in the question are 5 and 4, the let say December's revenue was 20 (the least common multiple of 4 and 5). So, we have that: Revenue in December = 20; Revenue in November = 20*2/5 = 8; Revenue in January = 8*1/4 = 2; The average of 8 and 2 is 5, so the store's revenue in December was 20/5=4 times that value. Answer: E.
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
25 Jun 2012, 04:29
Hi, Lets say, revenue in November = N was 2/5 of its revenue in December = D revenue in January = J As per given data, N = (2/5)D J = (1/4)N = 1/4 * 2/5 *D = (1/10)D D = \frac {x(N+J)}2, we need to find x, D = \frac {x((2/5)D+(1/10)D}2x = 4, Thus, Answer is (E). Regards,
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
26 Jun 2012, 10:11
Use plug in value.
Let Dec rev =100
Then Nov rev is 2/5 (100) => 40
Therefore Jan rev = 1/4(Nov rev) = 1/4(40) => 10
Hence Dec rev = x*( Nov rev+Jan rev)/2
100 = x* (40+10)/2
x = 100/25 => 4
Ans) E
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
26 Jun 2012, 14:09
N = 2/5*D or D = 5/2N
J= 1/4*N
avg (N+J) =( N+1/4*N)/ 2 =5/8*N
so, avg(N+J)/D = 4
E
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
29 Jun 2012, 03:05
SOLUTIONIf a certain toy store's revenue in November was 2/5 of its revenue in December and its revenue in January was 1/4 of its revenue in November, then the store's revenue in December was how many times the average (arithmetic mean) of its revenues in November and January?(A) 1/4 (B) 1/2 (C) 2/3 (D) 2 (E) 4 Probably, for most people it would be easier to solve such kind of questions by picking numbers. Notice that January is linked with November and November is linked with December. So, we should pick some smart number for December's revenue. Since the denominators in the question are 5 and 4, then let say December's revenue was 20 (the least common multiple of 4 and 5). So, we have that: Revenue in December = 20; Revenue in November = 20*2/5 = 8; Revenue in January = 8*1/4 = 2; The average of 8 and 2 is 5, so the store's revenue in December was 20/5=4 times that value. Answer: E.
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
11 Jul 2012, 22:00
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Bunuel,
The answer is perfect, but I think there is some confusion:-
You have written:-
Revenue in December = 20;
Revenue in November = 20*2/5 = 8;
Revenue in December = 8*1/4 = 2;
I think it should be:-
Revenue in December = 20;
Revenue in November = 20*2/5 = 8;
Revenue in January = 8*1/4 = 2;
Rgds
Rahul Goel
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
12 Jul 2012, 01:04
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Re: If a certain toy store's revenue in November was 2/5 of its [#permalink]
12 Jul 2012, 01:24
600 level. if we translate can write: N= 2/5 D and J = 1/4 N Now observing and substituting we obtaine N = 4J .......ravenues of November and January is 4. E is the answer.
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Re: If a certain toy store's revenue in November was 2/5 of its
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12 Jul 2012, 01:24
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