Question

Which of the following numbers below are not the decimal expansion of irrational number?

• A. $7.23$
• B. $\mathrm{2.01001000100001......}$
• C. $0.324$
• D. $10.069$

Answer 1

Answer: (A), (C), (D)

$10.069$

We know that decimal expansion of irrational numbers is non terminating non repeating.

Option (a) $7.23$ is a rational number because it has non terminating but repeating decimal expansion.

Option (b) $\mathrm{2.01001000100001......}$ is am irrational number because it has non terminating non repeating decimal expansion

Similarly,
option (c) and (d) are rational numbers with terminating expansion and non terminating repeating expansion respectively.

Only option (b) has decimal expansion of irrational number.
Required answer will be (a), (c), and (d).