Problem Solving

karan.7045 wrote:How to solve the root questions ,For example wat is the value of root 4 + cubth root of 4 + 4th root of 4.
I got stuck on a similar kind of question on GMAT

GMAT will never ask to find out the exact value of that.
The problem you are talking about is as follows,

If M = (square root of 4 + cube root of 4 + fourth root of 4), then the value of M is:

A. Less than 3
B. Equal to 3
C. Between 3 and 4
D. Equal to 4
E. Greater than 4

To answer this problem, we only need an estimation of the value.
As 4 > 1, any root of 4 will be greater than 1.
Now, square root of 4 = 2
Cube root of 4 will be greater than 1 but less than square root of 2.
So, 1 < cube root of 4 < 2
Similarly, 1 < fourth root of 4 < 2

Hence, M must be greater than (2 + 1 + 1) = 4

The correct answer is E.