OG- DS #128

[klamation]

If x is an integer, is x|x| < 2x?

1) x < 0
2) x = -10


OA is D


Can someone explain why statement 1 is sufficient please?

If x = -1, then x|x| = -1 and 2x = -2, so the answer is NO
But, if x = -3, then x|x| = -9 and 2x = -6, so the answer is YES

Therefore, this statement should be NOT SUFFICIENT. What am I missing?

[rey.fernandez]

In my edition, the question stem reads:

If x is an integer, is x|x| < 2^x?

Check your text again...

With this question, (1) is sufficient because the left side of the inequality is negative while the right side is positive.

[klamation]

Thanks, my book definitely has 2x instead of 2^x so mine must be a typo.

[eccentric]

With the version of question given ....
1 is insufficient to answer the problem as
x< 0 means x can take following values -1, -2 ,-3,-4 etc
with -1 lhs > rhs
-2 lhs = rhs
-3 lhs < rhs
hence there is no unique solution set for this...
option reduced to BCE
with
2. x =-10 is sufficeint enough to conclude hence B must be answer
???? i m correct on this.....

[jazzcat4u]

my book has this typo - reads 2x NOT 2^x - thanks for the clarity