A bag contains 3 purple, 4 green, 4 blue, and 4 white marbles.  What is the probability of taking a marble that is not purple?

pohnpei397 | Certified Educator

There is a 12 in 15 chance of getting a marble that is not purple.  You can also state this by saying that there is a 4 in 5 chance of getting that kind of a marble or you can say that the chance is 80%.

The way to figure this out is simply to look at the numbers of the various colors of marbles that are in the bag.  The bag has 15 total marbles in it.  Of those marbles, 12 are not purple.  When you reach in to get a marble, you have an equal chance to get any particular marble.  12 of those chances will get you non-purple marbles and 3 will get you purple marbles.

hala718 | Certified Educator

The bag contains :

3 Purple

4 green

4 blue

4 white

The total number of marbles is 15

The chances of teking a marble that is a purple = 3/15

Then the probability of taking a marble that is not purple = 1-3/15= 12/15

OR:

The probability of taking a purple = probability of taking green + blue + white= 4/15 + 4/15 + 4/15= 12/15.

neela | Student

The total number of mables in the bag = 3 purple + 4 green + 4 blue + 4white =15.

So there could be  any one of the 15 of the marbles you get in a single draw .

The number of chances of the drawn ball is purple = 3.  and not purple = 15-3 =12.

So the probability that the drawn marble is not purple = 12/15 = 4/5