Operations on Radical Expressions

grkmurthy · Senior Consultant Joined: 14 Oct 2007 Posts: 37

What is the value of square root{ cube root(0.000729)}?

(1) 0.06

(2) 0.30

(3) 0.09

(4) 0.03

(5) 0.60

sid · Associate Joined: 06 Nov 2007 Posts: 8

square root{ cube root(0.000243)}?

I think there is something wrong with the question.

square root is raising a number to the power of 1/2

Cube root is raising a number to the power of 1/3

we can write square root{ cube root(0.000243)}? as {(0.000243)^1/3}^1/2

which is (0.000243)^(1/6) which is {243 / 10^6}^1/6.
243 is 3^5 and not 3 ^ 6. So, we will not get any of the answers mentioned.

grkmurthy · Senior Consultant Joined: 14 Oct 2007 Posts: 37

Yes sir, you are right. The number should be Square root{cube root(0.000729)}.

sid · Associate Joined: 06 Nov 2007 Posts: 8

then the answer will be 0.3. Choice (B).

Please confirm if that is the correct answer.