when two digit number KY is multiplied by itself, the result is the 3 digit number ZLK i.e(KY) x(KY) = ZLK. The number that K stands for is

a)1 or 9

b)2 or 6

c)3

d)1

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- Mar 26th 2009, 02:23 AM #1

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- Mar 26th 2009, 02:59 AM #2

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- Mar 26th 2009, 03:58 AM #3

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Hello, kl050196!

We can solve this by Elimination.

When a 2-digit number $\displaystyle KY$ is squared,

the result is the 3-digit number $\displaystyle ZLK$ . . . i.e $\displaystyle (KY)^2 \:=\: ZLK$

The number that $\displaystyle K$ stands for is:

. . $\displaystyle (a)\;1\text{ or }9 \qquad (b)\;2\text{ or }6 \qquad (c)\;3 \qquad (d)\;1$

The answer cannot be (b) because a square cannot end in 2.

The answer cannot be (c) because a square cannot end in 3.

Therefore . . .