We can set up a proportion since we know the ratio between the # of purple marbles and the # of green marbles.
A ratio is a way to compare two different values: for every 8 purple marbles there are 5 green marbles
<h2></h2><h2 /><h2>when we cross multiply, we get 5p = 240 </h2><h2>we divide both sides by 5 to isolate the variable </h2><h2 /><h3><u>There are 48 purple marbles </u></h3>