goodyear2013 wrote:

If a is an even integer and a/18 is an odd integer, which of the following is NOT an even integer?

A (a^2)/54

B (a^2)/12

C (a^2)/9

D (a^2)/6

E (a^2)/2

"a is an even integer"

implies a has at least one 2 as a factor.

"a/18 is an odd integer"

18 = 2*9

When you divide a by 18, all its 2s get canceled. Since 18 has only one 2, it means a had only one 2 too.

So a^2 has 2^2 = 4 as a factor but not 8.

Since 12 has two 2s as well, both the 2s of a^2 will get canceled and hence you will not get an even integer.

All other options cancel only a single 2 of a^2.

Answer (B)

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