Given a bag with 12 marbles, if 5 are red and 7 are blue. What is the probability of picking a blue marble on your first try?

Answer 1

Hi Trezmynn,

Since this is a "fractions" problem, let's look at it that way.

We are told that 7 of the 12 marbles are blue. How would we write that as a fraction? Easy, it's:

7

——

12

That's because 7/12 of the marbles are blue.

And that's really all there is to this problem. The chances (probability) of picking one of the 7 blue marbles out of the 12 total is 7 / 12. We can also say "7 in 12".

Bonus question :-)

Why did the question say "on your first try"? Think about it. What happens after you remove one of the marbles?

Hope that helps!