A, B, C are three consecutive positive integers (A>B>C

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M7MBA: Moderator; Posts: 2058; Joined: Sun Oct 29, 2017 4:24 am; Thanked: 1 times; Followed by:5 members

A, B, C are three consecutive positive integers (A>B>C

by M7MBA » Thu Jun 14, 2018 11:34 pm

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A, B, C are three consecutive positive integers (A>B>C). What is the value of the expression 2A +B +3C?

A. 6A+7.
B. 5A+1.
C. 5A-1.
D. 6A-5.
E. 6A-7.

The OA is the option E.

Why is E the correct answer? I got the option A. Could anyone help me here? Please. Thanks in advance.

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Source: Beat The GMAT — Problem Solving | Thu Jun 14, 2018 11:34 pm

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by GMATGuruNY » Fri Jun 15, 2018 2:28 am

M7MBA wrote:A, B, C are three consecutive positive integers (A>B>C). What is the value of the expression 2A +B +3C?

A. 6A+7.
B. 5A+1.
C. 5A-1.
D. 6A-5.
E. 6A-7.

Let A=3, B=2 and C=1.
2A + B + 3C = (2*3) + 2 + (3*1) = 11.
Now plug A=3 into the answers to see which yields the value in blue.
Only E works:
6A-7 = (6*3) - 7 = 18 -7 = 11.

The correct answer is E.

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by [email protected] » Fri Jun 15, 2018 5:23 pm

Hi All,

We're told that A, B, C are three consecutive positive integers and A > B > C. We're asked for the value of the expression (2A +B +3C). This question can be solved rather easily by TESTing VALUES (as Mitch has shown). You could also approach it Algebraically.

Since the three variables are CONSECUTIVE INTEGERS and A > B > C, we can write all three variables in terms of A...
A = A
B = A-1
C = A-2

Thus, the value of 2A + B + 3C can be written as...
2A + (A-1) + 3(A-2) =
2A + A - 1 + 3A - 6 =
6A - 7

Final Answer: E

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Rich

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by Scott@TargetTestPrep » Mon Apr 29, 2019 8:10 am

M7MBA wrote:A, B, C are three consecutive positive integers (A>B>C). What is the value of the expression 2A +B +3C?

A. 6A+7.
B. 5A+1.
C. 5A-1.
D. 6A-5.
E. 6A-7.

Since the integers A, B, and C are consecutive integers (with A > B > C) and we see that the answer choices are in terms of A, we can say B = A - 1 and C = A - 2. Thus:

2A + B + 3C = 2A + A - 1 + 3(A - 2) = 3A - 1 + 3A - 6 = 6A - 7

Answer: E

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