Question

The set of irrational numbers includes all of the following except --



A
169\sqrt{169}
169
​


B
0.454554555...

C
�\piπ

D
124\sqrt{124}
124
​

Answer 1

To identify which of the options is not an irrational number, let's analyze each one:

A. \( 169\sqrt{169} \)
This simplifies to \( 169 \times 13 = 2197 \), which is a rational number (an integer).

B. \( 0.454554555... \)
This is a repeating decimal, specifically a rational number.

C. \( \pi \)
This is a well-known irrational number.

D. \( 124\sqrt{124} \)
This simplifies to \( 124 \times \sqrt{124} \), which involves the square root of a non-perfect square (124 is not a perfect square), making this an irrational number.

From the above analysis, options A and B are rational numbers. However, since the question asks for the option that is not an irrational number, the correct answer is:

**A. \( 169\sqrt{169} \)** (which equals 2197, a rational number).