Question

Each marble bag sold by Hans's Marble Company contains 8 purple marbles for every 5 green marbles. If a bag has 30 green marbles, how many purple marbles does it contain?

Answer 1

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

$\frac{8}{5} = \frac{p}{30}$

when we cross multiply, we get 5p = 240

we divide both sides by 5 to isolate the variable

There are 48 purple marbles