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Math Expert
Joined: 02 Sep 2009
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If a, b, c, and d are consecutive integers and a < b < c < d, what is
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 22 Jan 2018, 00:54
Question Stats:
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If a, b, c, and d are consecutive integers and a < b < c < d, what is the average (arithmetic mean) of a, b, c, and d in terms of d? (A) \(d - \frac{5}{2}\) (B) \(d - 2\) (C) \(d - \frac{3}{2}\) (D) \(d + \frac{3}{2}\) (E) \(\frac{4d-6}{7}\)
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Manager
Joined: 16 Jan 2018
Posts: 89
Location: New Zealand
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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22 Jan 2018, 01:02
Since they are consecutive integers, therefore a=d-3; b=d-2; c=d-1; Taking average, (d-3+d-2+d-1+d)/4 = (4d-6)/4 = d-3/2 Option C. Sent from my ONE E1003 using GMAT Club Forum mobile app
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Retired Moderator
Joined: 27 Oct 2017
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WE: General Management (Education)
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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22 Jan 2018, 06:05
Please see my approach  Bunuel wrote: If a, b, c, and d are consecutive integers and a < b < c < d, what is the average (arithmetic mean) of a, b, c, and d in terms of d?
(A) d – 5/2
(B) d – 2
(C) d – 3/2
(D) d + 3/2
(E) (4d – 6)/7
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Intern
Joined: 27 Jan 2017
Posts: 20
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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22 Jan 2018, 07:11
Bunuel wrote: If a, b, c, and d are consecutive integers and a < b < c < d, what is the average (arithmetic mean) of a, b, c, and d in terms of d?
(A) d – 5/2
(B) d – 2
(C) d – 3/2
(D) d + 3/2
(E) (4d – 6)/7 Answer: C Since consecutive integers, thus a = d-3 b = d-2 c = d-1 Mean = (a + b +c + d) / 4 Substituting a, b and c in above we get option C
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Senior Manager
Joined: 31 Jul 2017
Posts: 499
Location: Malaysia
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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22 Jan 2018, 07:36
Bunuel wrote: If a, b, c, and d are consecutive integers and a < b < c < d, what is the average (arithmetic mean) of a, b, c, and d in terms of d?
(A) d – 5/2
(B) d – 2
(C) d – 3/2
(D) d + 3/2
(E) (4d – 6)/7 As the numbers are consecutive, let the numbers be c-2, c-1,c , c+1 A.M = (4c-2)/4 = c -(1/2).. Also, as d = c+1 from above equation, c = d - 1 So, AM = d -(3/2)
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Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 10477
Location: Pune, India
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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22 Jan 2018, 22:21
The moment I see consecutive integers and a < b< c< d, I think of 1,2 ,3 ,4. Average is 2.5 which is 4 - 1.5 i.e. d - 3/2 Answer (C)
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Manager
Joined: 03 Oct 2016
Posts: 118
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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22 Jan 2018, 22:29
1. Av= \(\frac{(A+D)}{2}\) (as it is consecutive evenly spaced numbers)
2. Range = D-A=3 (as it is consecutive numbers with increment of 1)
3. Substitute A= D-3 in 1. Av=\(\frac{(D-3+D)}{2}\) ->Av=\(\frac{(2D-3)}{2}\)
4. After dividing by 2 it becomes Av=D-\(\frac{3}{2}\). Answer (C)
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Target Test Prep Representative
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2800
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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23 Jan 2018, 07:53
Bunuel wrote: If a, b, c, and d are consecutive integers and a < b < c < d, what is the average (arithmetic mean) of a, b, c, and d in terms of d?
(A) d – 5/2
(B) d – 2
(C) d – 3/2
(D) d + 3/2
(E) (4d – 6)/7 We can label our consecutive integers as: d c = d - 1 b = d - 2 a = d - 3 Using the formula for the arithmetic average (mean), we have: average = (d + d - 1 + d - 2 + d - 3)/4 = (4d - 6)/4 = 4d/4 - 6/4 = d - 3/2 Answer: C
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Director
Joined: 20 Feb 2015
Posts: 722
Concentration: Strategy, General Management
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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19 Aug 2018, 09:45
Bunuel wrote: If a, b, c, and d are consecutive integers and a < b < c < d, what is the average (arithmetic mean) of a, b, c, and d in terms of d?
(A) \(d - \frac{5}{2}\)
(B) \(d - 2\)
(C) \(d - \frac{3}{2}\)
(D) \(d + \frac{3}{2}\)
(E) \(\frac{4d-6}{7}\) since the integers are consecutive . in terms of d we have sum = d + (d-1) + (d-2) + (d-3) average = \(\frac{(4d-6)}{4}\) =d-3/2
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Re: If a, b, c, and d are consecutive integers and a < b < c < d, what is
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19 Aug 2018, 09:45
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