Question

If 20% of x = y, then y% of 20 is same as

• A. 10% of x
• B. 20% of x
• C. 15% of x
• D. 4% of x

Answer 1

The Correct Option is D

To solve this problem, let's start with the given equation:
\[ 20\% \text{ of } x = y \]
This can be written as:
\[ 0.2x = y \]
Now, we need to find \( y\% \text{ of } 20 \). This can be expressed as:
\[ \frac{y}{100} \times 20 \]
Substitute \( y = 0.2x \) into the equation:
\[ \frac{0.2x}{100} \times 20 \]
Simplify the expression:
\[ \frac{0.2x \times 20}{100} = \frac{4x}{100} = 0.04x \]
So, \( y\% \text{ of } 20 \) is the same as:
Answer: D (4% of x)

Answer 2

We can check this by picking an easy number for x and seeing what y% of 20 actually comes out to, then matching that against each option.

1. Option A (10% of x): Taking \( x = 100 \), \( y = 20 \), and \( y\% \) of 20 is \( 0.20 \times 20 = 4 \). But 10% of x here is 10, so this option does not match.
2. Option B (20% of x): 20% of x here is 20, which also does not match the value 4 we found.
3. Option C (15% of x): 15% of x here is 15, again not matching 4.
4. Option D (4% of x): 4% of x here is 4, which matches the value we found for y% of 20.

Testing with \( x = 100 \) shows that y% of 20 always comes out to 4% of x, matching option D.

Let's summarize:

• Picking a simple value for x turns the problem into plain arithmetic.
• The result, 4, lines up only with 4% of x.

Therefore, the correct answer is D (4% of x).