If 40% of a number is 80, what is the number?

If 40% of a number is 80, what is the number?

• A. 200
• B. 160
• C. 180
• D. 220

Answer: (A)

To determine the number when 40% of it equals 80, you can set up the equation based on the relationship between percentages and their corresponding values. Start by expressing the problem mathematically: Let the unknown number be represented by \( x \). Since 40% of \( x \) equals 80, you can write the equation as: \[ 0.40x = 80 \] Next, to isolate \( x \), you can divide both sides of the equation by 0.40: \[ x = \frac{80}{0.40} \] Calculating the right side: \[ x = \frac{80}{0.40} = \frac{80}{\frac{4}{10}} = 80 \times \frac{10}{4} = 80 \times 2.5 = 200 \] Thus, the value of \( x \) is 200. This means that the number in question is indeed 200, as 40% of 200 is 80. This deduction process reveals that the correct answer represents a straightforward application of percentage calculations and algebraic manipulation.

To determine the number when 40% of it equals 80, you can set up the equation based on the relationship between percentages and their corresponding values.

Start by expressing the problem mathematically:

Let the unknown number be represented by ( x ). Since 40% of ( x ) equals 80, you can write the equation as:

[

0.40x = 80

]

Next, to isolate ( x ), you can divide both sides of the equation by 0.40:

[

x = \frac{80}{0.40}

]

Calculating the right side:

[

x = \frac{80}{0.40} = \frac{80}{\frac{4}{10}} = 80 \times \frac{10}{4} = 80 \times 2.5 = 200

]

Thus, the value of ( x ) is 200. This means that the number in question is indeed 200, as 40% of 200 is 80.

This deduction process reveals that the correct answer represents a straightforward application of percentage calculations and algebraic manipulation.