|
Probability is the |
# of possible favorable outcomes over (divided by)
# of total possible outcomes |
A jar contains 5 red, 3 purple, 2 blue and 4 orange marbles.
What is the probability that a blue marble be drawn?
2 marbles are blue. That is the number
of possible favorable outcomes
14 total marbles - - - - - - - the number of total possible outcomes
|
2
14 |
Must be reduced. Divide top and bottom by 2 |
1
7 |
probability that a red, purple or blue marble is drawn would be
5+3+2 = 10 = 10/2 = 5
14
14 14/2 7
probability that a yellow marble is drawn would be
0 = 0
14
Probability goes from 0(an impossible thing) to 1 ( a sure thing).
A number cube is rolled. It has faces 1, 2, 3, 4, 5, 6.
What is the probability that a number greater than 4 is rolled?
5 and 6 would be the only 2 possible favorable outcomes
So 2 would be the numerator (go on top).
There are 6 total possible outcomes, so 6 would be denominator, go on the bottom.
2 = 1
6 3
A standard deck of cards has 52 cards, 2 red suits, 2 black suits.
What is the probability that a black card or a 10 is drawn?
26 of the cards are black, There are 4 tens, but 2 of those are already
in the black cards. There are 2 red tens.
26 +2 = 28 possible favorable outcomes. 28 goes on top.
Total possible outcomes is 52, 52 goes on the bottom.
|
probability is 28
52 |
divide top and bottom by 4 |
7
13 |
