Geometry NOTES Date: __________
PROBABILITY:

a number from 0 to 1 that measures how likely it is that an event will happen.

Your answer can be represented by a fraction, decimal, or percent.

Some events will never occur, and some events will always occur
P(E): symbol that represents: “the probability of the event occurring”
( )
 number of outcomes possible in "E"
Total number of outcomes altogether
1. What is the probability of guessing the correct answer to a True-False question?
2. What is the probability of guessing the correct answer to a multiple choice question if there are 5 choices?
3. The letters “a, e, i, o, u” are vowels. If one letter of the alphabet is chosen at random, what is the probability it is a
vowel?
4. If you roll a single die once, what is the probability of rolling a 3?
5.

7.
6.
5.
  
the AREA of the region of the event total AREA of the entire region

9.
8. A circle is inscribed in a square. A point is chosen at random. What is the probability that the point lies in the shaded region?
9. A triangle is inscribed in a square. A point in the square is selected at random. What is the probability that the point lies in the shaded region?