Massive confusion over exponents at GMAT...

[gmat_2010]

Hi,

What does x^y^z mean? Does it mean (x^y)^z or x^(y^z).

All throughout my school this question killed me and I always got the right answers when I went for x^(y^z). But in the test prep companies' questions the answer is generally (x^y)^z = x^(y*z).

Today, I got a similar question while taking a test from GMAT Prep and went for the 2nd one. I was wrong! The solution had considered x^(y^z). Now, I need a definite answer. Could you all help? Thanks a lot!

[truplayer256]

In most cases, the GMAT usually has parentheses around expressions like x^y^z to make things more clear.

(x^y)^(z) obviously means x^(y*z) and x^(y^z) obviously means x raised to the y^z power. The question would be rather difficult to solve if the GMAT didn't have these kinds of parentheses.

[quant-master]

Hi,

What does x^y^z mean? Does it mean (x^y)^z or x^(y^z).

All throughout my school this question k!IIed me and I always got the right answers when I went for x^(y^z). But in the test prep companies' questions the answer is generally (x^y)^z = x^(y*z).

Today, I got a similar question while taking a test from GMAT Prep and went for the 2nd one. I was wrong! The solution had considered x^(y^z). Now, I need a definite answer. Could you all help? Thanks a lot!

x^y^z should mean x raised to the power of y, which in turn is raised to the power of z. Hence it should be x^(y^z)

Thanks,
Quant-Master

[gmat_2010]

[quote="quant-master"][quote="gmat_2010"]Hi,

What does x^y^z mean? Does it mean (x^y)^z or x^(y^z).

All throughout my school this question k!IIed me and I always got the right answers when I went for x^(y^z). But in the test prep companies' questions the answer is generally (x^y)^z = x^(y*z).

Today, I got a similar question while taking a test from GMAT Prep and went for the 2nd one. I was wrong! The solution had considered x^(y^z). Now, I need a definite answer. Could you all help? Thanks a lot![/quote]

x^y^z should mean x raised to the power of y, which in turn is raised to the power of z. Hence it should be x^(y^z)

Thanks,
Quant-Master[/quote]

I agree with you. I have solved the problems this way my whole life and I have been right all along. The GMAT Prep answer also used the same interpretation. I am going in with this concept. Just to let you know, GMAT Prep didn't use parentheses.