PS - Integers

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PS - Integers

by karthikpandian19 » Mon Dec 05, 2011 10:34 pm
If x and y are integers and 2x-y= 11, then 4x+ y CANNOT be

(A) -5(B) 1(C) 13(D) 17(E) 55

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by Anurag@Gurome » Mon Dec 05, 2011 10:38 pm
karthikpandian19 wrote:If x and y are integers and 2x-y= 11, then 4x+ y CANNOT be

(A) -5(B) 1(C) 13(D) 17(E) 55
2x - y = 11
4x - 2y = 22
4x + y = 3y + 22, which can be written as 3(y + 7) + 1

When we subtract 1 from 4x + y then it will be a multiple of 3.
Only 17 - 1 = 16, which is not a multiple of 3.

The correct answer is D.
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by sl750 » Mon Dec 05, 2011 10:42 pm
2x-y=11 or y=2x-11. Substitute value of y in 4x+y

6x-11. Since x is an integer. Replace x with values such as 1,2,3.. so on. Only choice D CANNOT be the value of 6x-11

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by [email protected] » Sat Dec 24, 2011 5:06 am
solving with simultaneous equations will also give a solution!!!
IT IS TIME TO BEAT THE GMAT

LEARNING, APPLICATION AND TIMING IS THE FACT OF GMAT AND LIFE AS WELL... KEEP PLAYING!!!

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by LalaB » Sat Dec 24, 2011 6:58 am
karthikpandian19 wrote:If x and y are integers and 2x-y= 11, then 4x+ y CANNOT be

(A) -5(B) 1(C) 13(D) 17(E) 55
2x-y=11 multiply this equation by 2
4x-2y=22

so, now we have

4x-2y=22
minus
4x+y=Z
--------------
-3y=22-z


(A) -5 ; -3y=22+5 y is an integer. eliminate A

(B) 1; -3y=22-1 y is an integer .eliminate B
(C) 13; -3y=22-13 y is an integer .eliminate C
(D) 17; -3y=22-17 . y=5/3 .so y is not an integer. D is correct
(E) 55; -3y=22-55 y is an 326integer. eliminate E

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by karthikpandian19 » Tue Dec 27, 2011 9:48 pm
OA is D

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by amit28it » Sat Dec 31, 2011 12:03 am
D is the correct answer.So it's easy question .how do you do ratios to solve problem related to it .Thanks .