If y is an odd number and x3y4=648, y=? 1) y is positive. 2) x is

Question

If y is an odd number and  x^3*y^4=648 , y=?

1) y is positive.

2) x is an integer.

kris19 · Answer

prob statement is: y is an odd number, and x^3*y^4=648
648 can be written as 2^3*3^4
s1: y is positive, but since y is not mentioned as an int, we can't know for sure the value of y, not sufficient
s2: x is an int, then y can be negative or positive, since power of y is 4, not sufficient

s1&s2: x is an int and y is positive, then for sure y is an int and y = 3, sufficient
ans: C

brains · Answer

VeritasKarishma  and  Bunuel  .

Help please!

I could not find any combinations other than y being 3 from first statement. So i think statement 1 is sufficient. Kindly explain . However OA is given as C in the post
Thanks

firas92 · Answer

Hi  brains

For statement 1 we can have the following cases

x=2, y=3

x=\sqrt {648}, y=1

Note that we are not told in statement 1 that  x  must be an integer

Hope this helps

Posted from my mobile device

TargetHEC · Answer

If y is an odd number and  x^3*y^4=648 , y=?

1) y is positive.

2) x is an integer.

The issue is,why would we need the first statement.Negative numbers are not even or odd. 2 must be sufficient

firas92 · Answer

All integers including negative ones must be either even or odd.

Even - {......, -6, -4, -2, 0, 2, 4, 6, ....}

Odd - {....., -5, -3, -1, 1, 3, ....}

Posted from my mobile device

TargetHEC · Answer

Ok, thanks for clearing up the misunderstanding I had. C makes sense then

KarishmaB · Answer

Without statement 2, y can be 1 and x = cube root of 648

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If y is an odd number and x3y4=648, y=? 1) y is positive. 2) x is

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GMAT Data Sufficiency (DS) Questions

If y is an odd number and x3y4=648, y=? 1) y is positive. 2) x is

Prep Toolkit

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My Rewards