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rs different from zero

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rs different from zero [#permalink]  06 Jul 2018, 09:33
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Question Stats:

66% (00:18) correct 33% (00:13) wrong based on 3 sessions
$$rs \neq 0$$

 Quantity A Quantity B $$(r+s)^2$$ $$r^2 + s^2$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
[Reveal] Spoiler: OA

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Re: rs different from zero [#permalink]  06 Jul 2018, 21:19
Carcass wrote:
$$rs \neq 0$$

 Quantity A Quantity B $$(r+s)^2$$ $$r^2 + s^2$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.

Here,

No information of the qty r and s are given, the only information is that $$rs \neq 0$$

so we can take two possibilities,

1. When both r and s are positive, let r= 1 and r=2

then QTY A = $$(r + s)^2 = 3^2 = 9$$

and QTY B =$$r^2 + s^2 = 1 + 4 = 5$$

So QTY A > QTY B

2. Now if r is positive and s is negative, let r = 1 and s = -2

then QTY A = $$(r + s)^2 = 1^2 = 1$$

and QTY B = $$r^2 + s^2 = 1 + 4 = 5$$
So QTY A < QTY B

Hence the option is D
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Re: rs different from zero   [#permalink] 06 Jul 2018, 21:19
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