Problem 129 - Introductory Algebra for College Students

Question

8 is \(40 \%\) of what number?

Step-by-Step Solution

Answer

The number is 20.

Step 1: Understand the problem and express it as an equation

The problem could be express as: '8 is 40% of what number?' or '8 is 40/100 of X'. This can be expressed as an equation: \( \frac{8}{X} = \frac{40}{100} \)

Step 2: Solve the equation by cross-multiplying

In order to solve for X, we can use cross-multiplication. This gives us the equation: \( 8*100 = 40*X \)

Step 3: Divide by 40

To isolate X, we divide both sides of the equation by 40. This gives us X= \( \frac{8*100}{40} \)

Step 4: Simplify the equation

By simplifying the equation from the previous step, we can find the value of X. This gives X=20.