Question

In a group of 140 students, 65 use Craigslist, 85 use eBay, and 20 use neither. A) how many students use both websites?

Answer 1

$\begin{gathered} 140\to\text{ students} \\ 20\to\text{ no use neither website} \\ 140-20=\text{ 120 students that uses websites} \\ 65+85=150\text{ studentes that uses Craigslist ans eBay} \\ 150-120\text{ = 30 students that uses both } \end{gathered}$