inequity 24

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inequity 24

by magical cook » Tue Dec 25, 2007 10:01 am
Is 1/p > r/(r^2+2) ?

1) p=r
2) r>0



[spoiler][spoiler]I was thinking A because wheter R is negative or positive, always 1/p will be bigger....no? but answer seems C - could anyone give me light pls? [/spoiler][/spoiler]
Source: — Data Sufficiency |

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by beingAndNothing » Tue Dec 25, 2007 12:18 pm
1/p > r/(r^2 + 2)

1) p = r

We can rewrite the eqn as

1/r > r/(r^2 + 2)

Now if r>0

1>r^2/(r^2+2) or
r^2/(r^2 + 2) < 1

The ineq. holds true

if r<0> 1, which is not possible. The ineq. does not hold true.

2) r>0 does not say anything about p. Hence insufficient.

But (1) & (2) together do say that 1/p > r/(r^2 + 2). Hence (C).