What number should be divided by $\sqrt{0.25}$ to give the result as 25?

Concept & Logic Translate the word problem directly into an algebraic equation, resolve the square root of the decimal first, and then isolate the unknown variable. Step-by-Step Solution * **Given:** Let the unknown number be $x$. The problem states: $\frac{x}{\sqrt{0.25}} = 25$. * **Calculation:** First, evaluate the square root in the denominator. $\sqrt{0.25} = 0.5$ * Substitute this back into the equation: $\frac{x}{0.5} = 25$ * Multiply both sides by $0.5$ to isolate $x$: $x = 25 \times 0.5$ * Dividing by $2$ is the same as multiplying by $0.5$: $x = 12.5$ Exam Strategy & Shortcut Memorize basic decimal roots. $\sqrt{0.25}$ is instantly $0.5$ (or $1/2$). The question effectively asks: "What number divided by half equals 25?". Dividing by a half is the same as multiplying by $2$. So, $x \times 2 = 25$. Therefore, $x$ must be $12.5$. Common Pitfall Incorrectly evaluating $\sqrt{0.25}$ as $0.05$ instead of $0.5$, which throws off the decimal placement of the final answer entirely. Final Answer **Therefore, the correct answer is 12.5.**