Question

If two numbers are respectively $20\%$ and $50\%$ of a third number, what is the percentage of the first number to the second?

• A. $10$
• B. $20$
• C. $30$
• D. $40$

Answer 1

The correct option is D $40$

Let the third number be $x$

Then first number $=20\%$ of $x$ $=\frac{20x}{100}$

Second number $=50\%$ of $x$ $=\frac{50x}{100}$

Percent of first number to the second $=\frac{\frac{20x}{100}}{\frac{50x}{100}}\times 100$

$=\frac{20\times 100}{50}=40\%$