Question

Which number does not belong with the other three? Explain your reasoning.

• A. $-\frac{11}{12}$
• B. $25.075$
• C. $\sqrt{8}$
• D. $-3.\overline{3}$

Answer 1

The correct option is C

$\sqrt{8}$

Given number: $-\frac{11}{12}$, $25.075$, $\sqrt{8}$, $-3.\overline{3}$.

We know that a number, a which can be represent in the form of $\frac{\mathrm{p}}{\mathrm{q}}$, $\mathrm{p}$and $\mathrm{q}$ are integers and $\mathrm{q}\ne 0$, is a rational number.

Decimal expansion of rational number is terminating or non terminating recurring.

Square root of a not perfect square number is a irrational number.

Thus, $-\frac{11}{12}$, $25.075$ and $-3.\overline{3}$ are rational number

and $\sqrt{8}$ is a irrational number.

Hence, option C is correct.