What is the sum of 3 consecutive integers?
(1) The sum of the 3 integers is less than the greatest of the 3 integers.
(2) Of the 3 integers, the ratio of the least to the greatest is 3.
OA B
Source: Official Guide
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What is the sum of 3 consecutive integers?
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BTGmoderatorDC
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let the three numbers be (x−1),x,(x+1)
from statement (1), (x−1)+x+(x+1)<(x+1)
so 3x<x+1
2x<1
x<1/2 ---. so no definite value for x (insufficient)
from statement (2), (x−1 )/ (x+1)=3
so x=−2 and the three numbers are −1,−2,−3 and the sum = −6--> sufficient
Answer : B
from statement (1), (x−1)+x+(x+1)<(x+1)
so 3x<x+1
2x<1
x<1/2 ---. so no definite value for x (insufficient)
from statement (2), (x−1 )/ (x+1)=3
so x=−2 and the three numbers are −1,−2,−3 and the sum = −6--> sufficient
Answer : B
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Brent@GMATPrepNow
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Target question: What is the sum of 3 consecutive integers?BTGmoderatorDC wrote:What is the sum of 3 consecutive integers?
(1) The sum of the 3 integers is less than the greatest of the 3 integers.
(2) Of the 3 integers, the ratio of the least to the greatest is 3.
OA B
Source: Official Guide
Statement 1: The sum of the 3 integers is less than the greatest of the 3 integers.
There are several sets of three consecutive integers that satisfy statement 1. Here are two:
Case a: The numbers are {-1, 0, 1}. In this case the sum is 0, and 0 is less than the biggest number in the set (1). The answer to the target question is the sum of the integers is 0
Case b: The numbers are {-2, -1, 0}. In this case the sum is -3, and -3 is less than the biggest number in the set (0). The answer to the target question is the sum of the integers is -3
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: Of the 3 integers, the ratio of the least to the greatest is 3.
Let x = the smallest integer
So, x + 1 = the middle integer
And, x + 2 = the greatest integer
From statement to we can write: (x+2)/(x) = 3
Multiply both sides of the equation by x to get: x + 2 = 3x
Subtract x from both sides to get: 2 = 2x
Solve: x = 1
Since x is the smallest integer, we now know that the three consecutive integers are {1, 2, 3}
The answer to the target question is the sum of the integers = 1 + 2 + 3 = 6
Since we can answer the target question with certainty, statement 2 is SUFFICIENT
Answer: B
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Brent
Brent Hanneson - Creator of GMATPrepNow.com
