Question

If it is assumed that $60\%$ of those who receive a questionnaire by mail will respond and $300$ responses are needed, what is the minimum number of questionnaires that should be mailed?

• A. $400$
• B. $420$
• C. $480$
• D. $500$
• E. $600$

Answer 1

Answer: (D)

$500$

Let minimumn number of questionaires that should be mailed be $x$.
According to question,
$60$%$x=300$
$\frac{60}{100}$$x=300$
$\therefore x=300\times \frac{100‘}{60}$
$x=500$
Thus, munimum number of questioaire that should be mailed is 500.