## If k is an odd integer, which of the following must be an even integer?

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### If k is an odd integer, which of the following must be an even integer?

by AAPL » Thu May 13, 2021 5:38 am

00:00

A

B

C

D

E

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Magoosh

If k is an odd integer, which of the following must be an even integer?

A. $$k^2-4$$

B. $$3k+2$$

C. $$2k+1$$

D. $$\dfrac{12k}{8}$$

E. $$\dfrac{6k}{3}$$

OA E

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### Re: If k is an odd integer, which of the following must be an even integer?

by [email protected] » Sat May 15, 2021 5:50 am
AAPL wrote:
Thu May 13, 2021 5:38 am
Magoosh

If k is an odd integer, which of the following must be an even integer?

A. $$k^2-4$$

B. $$3k+2$$

C. $$2k+1$$

D. $$\dfrac{12k}{8}$$

E. $$\dfrac{6k}{3}$$

OA E
The key word in must, which means the correct answer will yield an EVEN value for ALL odd values of k.
So, if we find an odd value for k that does NOT yield an even output, then we can eliminate that answer choice.

Let's see what happens when k = 1 (1 is a nice odd integer to work with)
Plug k = 1 to get...
A. 1² – 4 = -3. -3 is NOT even. ELIMINATE A
B. 3(1) + 2 = 5. 5 is NOT even. ELIMINATE B
C. 2(1) + 1 = 3. 3 is NOT even. ELIMINATE C
D. 12(1)/8 = 3/2. 3/2 is NOT even. ELIMINATE D

By the process of elimination, the correct answer must be E

Cheers,
Brent

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