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How to solve this methematically?

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How to solve this methematically?

by gmatrant » Sat Oct 27, 2007 9:55 am
I solved this by rote method, i.e substituting values and then using POE, but mathematically how does one solve this

If x is an integer and y=3x+2 which of the following CANNOT be a divisor of y?
A) 4
B) 5
C) 6
D) 7
E) 8
OA is C
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by wongee » Sat Oct 27, 2007 11:00 am
Here's a try:

x in an integer. So, 3x is a multilple of 3.

Eg. 3 , 6, 9, 12, 15, 18, 21, 24 etc...
y=3x+2
So, 3 , 6, 9, 12, 15, 18, 21, 24 etc...
+2 = 5, 8, 11, 14, 17, 20, 23, 26

Now look at the choices, 6 is the answer!

Pls correct me if I am wrong!
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by samirpandeyit62 » Sat Oct 27, 2007 9:52 pm
If x is an integer and y=3x+2 which of the following CANNOT be a divisor of y?

y =3x + 2 i.e y is a multiple of 3 + 2 so it will not be divisible by3

now if it is not divisible by 3, then it cannot be divisble by 6, coz for any nos to be divisible by 6 it has to be divisible by 2 & 3

C 6
Regards
Samir
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