Question:medium

If ‘x’ is positive , is  $^4 \sqrt{x}   >  ^3 \sqrt{x} $
Statement 1: 0.5 < x < 2 
Statement 2:  $12x^2 - 7x +1 = 0$

Updated On: Jan 13, 2026
  • statement (1) alone is sufficient to answer the question
  • statement (2) alone is sufficient to answer the question
  • both the statements together are needed to answer the question
  • statement (1) alone or statement (2) alone is sufficient to answer the question
  • neither statement (1) nor statement (2) suffices to answer the question
Show Solution

The Correct Option is B

Solution and Explanation

The correct answer is option (B):
statement (2) alone is sufficient to answer the question

The question asks if $^4 \sqrt{x} > ^3 \sqrt{x}$ given that x is positive. This inequality can be rewritten as $x^{1/4} > x^{1/3}$.

To determine when this inequality holds, we can consider the relationship between the exponents. Since x is positive, we can analyze the behavior of the function $f(x) = x^a$.

If x > 1, then $x^{1/4} > x^{1/3}$ is false because the exponent 1/3 is greater than 1/4, and for x > 1, a larger exponent leads to a larger value. So, if x > 1, $x^{1/3} > x^{1/4}$.

If 0 < x < 1, then $x^{1/4} > x^{1/3}$ is true because for 0 < x < 1, a smaller exponent leads to a larger value. So, if 0 < x < 1, $x^{1/4} > x^{1/3}$.

If x = 1, then $x^{1/4} = 1$ and $x^{1/3} = 1$, so $x^{1/4} = x^{1/3}$, and the inequality $x^{1/4} > x^{1/3}$ is false.

Therefore, the inequality $^4 \sqrt{x} > ^3 \sqrt{x}$ is true if and only if 0 < x < 1.

Now let's analyze the statements.

Statement 1: 0.5 < x < 2
This statement tells us that x is in the range (0.5, 2).
If x is in the range (0.5, 1), then the inequality $^4 \sqrt{x} > ^3 \sqrt{x}$ is true.
If x is in the range [1, 2), then the inequality is false.
Since Statement 1 allows for values where the inequality is true and values where it is false, it is not sufficient.

Statement 2: $12x^2 - 7x + 1 = 0$
Solve using factoring:

We look for two numbers that multiply to 12 and add to -7. They are -3 and -4.

Rewrite the equation:
$12x^2 - 4x - 3x + 1 = 0$
$4x(3x - 1) - 1(3x - 1) = 0$
$(4x - 1)(3x - 1) = 0$

So the solutions are:
$4x - 1 = 0 \Rightarrow x = 1/4$
$3x - 1 = 0 \Rightarrow x = 1/3$

Both values 1/4 and 1/3 satisfy 0 < x < 1.
We know from the initial inequality analysis that for any x in this interval, $^4 \sqrt{x} > ^3 \sqrt{x}$ is true.

Therefore, Statement 2 alone guarantees a definite “YES” to the question. It is sufficient.

The final answer is: $\boxed{\text{statement (2) alone is sufficient to answer the question}}$.
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