A. $250
B. $40
C. $25
D. $400
E. None of these
$2 \frac{1}{2} \% \text{ of } \square = $10
Answer (1)
Convert the percentage to a decimal: 2 2 1 % = 0.025 .
Set up the equation: 0.025 x = 10 .
Solve for x : x = 0.025 10 = 400 .
The unknown value is 400 .
Explanation
Problem Analysis Let's analyze the problem. We are given that 2 2 1 % of an unknown number is equal to $10 . We need to find this unknown number and choose the correct option from the list.
Setting up the Equation Let x be the unknown number. We can write the given information as an equation: 2 2 1 % × x = 10
Converting Percentage to Decimal First, convert the percentage to a decimal. We have 2 2 1 % = 2.5% = 0.025 . So the equation becomes: 0.025 x = 10
Solving for x Now, solve for x by dividing both sides of the equation by 0.025 : x = 0.025 10
Calculating the Value of x Performing the division, we find: x = 400
Selecting the Correct Option Comparing our result with the given options, we see that option D is $400 , which matches our calculated value. Therefore, the correct answer is D.
Examples
Imagine you are calculating the original price of an item after knowing the discount percentage and the discount amount. If an item has a discount of 2.5% and the discount amount is $10 , you can use the same method to find the original price of the item, which in this case would be $400 . This type of calculation is useful in retail and personal finance for understanding pricing and discounts.
