Question 135710
How many marbles are the in total? {{{8 + 12 + 10}}} = {{{30}}}

How many are orange? {{{12}}}

So what are the odds of picking an orange marble??  12 out of 30 = {{{12/30}}} = {{{.4}}}

If Jen use this same set of marbles over and over again, picking one out, checking the colr and then putting it back. Each time she picked a marble, the odds are 4/10 that it would be an orange one.

Use a ratio

{{{4/10 = x /120}}}
{{{(4*120)/10 = x }}}
{{{ 48 = x }}}

Check your answer. is 48 = 120*0.4?