Question: Negative Decimal Exponent

Comment on Negative Decimal Exponent

I did this a slightly different way, but still got C. I did 16 ^-1/4. Then knowing 16 = X, -1 = A and 4 = B, I used the formula (B√x)^A to get (4√16) ^-1 = (2) ^-1, which is 1/2^1 = 1/2.
gmat-admin's picture

Perfect! That approach also works.

I found it this way..
1/(16)1/4
1/ 4 ssquare power 1/4
1/4 power1/2
1/2
gmat-admin's picture

Very nice! That works too.

Will there ever be a scenario where we have to solve a problem like 729 ^-0.333 or something along those lines?
gmat-admin's picture

Yes, it's possible to be required to evaluate a power like 729^(-0.333.....), just as long as the decimal can be converted to a decimal (e.g., -0.333333.... can be rewritten as -1/3)

In this case, 729^(-0.333.....) = 729^(-1/3) = 1/(729^1/3) = 1/9

Cheers,
Brent

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