If p and x are integers , is x divisible by 11?

If p and x are integers, is x divisible by 11?

1) x=2(p-3)
2) 2p+5 is divisible by 11

from 2) we get that p could be for example, 3, 14, 25...

if we use the value 3 in 1) we get x=0 which is not divisible by 11, and if p=14->x=22, so imo E.

0 is divisible by 11, in fact by any other number than 0 itself. So the answer is C.

Ok thanks for clearing that up.

One question: According to the second statemet 2p could also equal -5 since 2p+5 is divisible by 11 so 2p+5 could also be zero.. if you plug it into the first statement then it is not divisible by 11 anymore. could yomeone possibly clarify this??

Many thanks!

We are told that p is an integer, thus 2p cannot equal to -5 because in this case p is not an integer.

Hope it's clear.

We are told that p is an integer, thus 2p cannot equal to -5 because in this case p is not an integer.

Hope it's clear.[/quote]

Understood, many thanks!

Target question: Is x divisible by 11?

Given: p and x are integers

Statement 1: x = 2p - 6
This statement doesn't FEEL sufficient, so I'll TEST some values.
Case a: p = 10. So, x = 2(10) - 6 = 14. If x = 14, then the answer to the target question is NO; x is NOT divisible by 11
Case b: p = 14. So, x = 2(14) - 6 = 22. If x = 22, then the answer to the target question is YES; x IS divisible by 11
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: 2p + 5 is divisible by 11
There is no information about x.
So, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 2 tells us that 2p + 5 is divisible by 11
This means that 2p+5 = 11k for some integer k

Statement 1 tells us that x = 2p - 6
My goal is to fiddle with this equation so we can use the fact that 2p+5 = 11k
Notice that we can take the equation x = 2p - 6 and REWRITE it as x = 2p + 5 - 11 [since this new equation still simplifies to be x = 2p-6]
We can now replace 2p+5 with 11k to get: x = 11k - 11
We can now factor out 11 to get: x = 11(k - 1)
This tells us that x is a MULTIPLE of 11, which also means 11 is divisible by 11
So, the answer to the target question is YES; x IS divisible by 11
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer: C

Cheers,
Brent

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