Question

In a recent survey of college-educated adults, 351 indicated that they regularly work more than 45hrs a week. If this represents 39% of those surveyed, how many people were in the survey?

Answer 1

Recall that the y% of x is given by the following expression:

$x\cdot\frac{y}{100}\text{.}$

Now, let S be the number of people that were in the survey, then, we know that 39% of S is 351, then we can set the following equation:

$351=S\cdot\frac{39}{100}\text{.}$

Multiplying the above equation by 100/39 we get:

$\begin{gathered} 351\times\frac{100}{39}=S\cdot\frac{39}{100}\times\frac{100}{39}, \\ S=900. \end{gathered}$

Answer: 900.