NAME _____________________________________________ DATE ____________________________ PERIOD _____________
Practice Probability WS
1. Suppose 7 points on a circle are chosen at random, as shown at the right.
a. Using the letters A through E, how many ways can the points on the circle be named?
b. If one point on the circle is fixed, how many arrangements are possible?
2. A group of 4 girls and 4 boys is randomly seated at a round table. What is the probability that the arrangement is
boy-girl-boy-girl?
3. In chemistry lab, you need to test six samples that are randomly arranged on a circular tray.
a. What is the probability that the arrangement shown at the right is produced?
b. What is the probability that test tube 2 will be in the top middle position?
4. Use the figure below. Assume that the balls are aligned at random.
a. What is the probability that in a row of 8 pool
balls, the solid 2 and striped 11 would be first
and second from the left?
b. What is the probability that if the 8 pool balls
were mixed up at random, they would end up the
order shown?
c. What is the probability that in a row of seven
balls, with three 8 balls, three 9 balls, and one 6
ball, the three 8 balls would be to the left of the
6 ball and the three 9 balls would be on the
right?
d. If the eight original balls were randomly
rearranged and formed a circle, what is the
probability that the 6 ball is next to the 7 ball?
5. DISPLAY The Art Club is displaying the students’ works in the main hallway. In a row of 12 randomly ordered
paintings, what is the probability that Tim’s and Abby’s paintings are in the 6th and 7th positions?
6. TRY-OUTS Ten students made call-backs for the three lead roles in the school play. What is the probability Sarah,
Maria, and Jimenez will be chosen for the leads?
7. SECURITY Parking stickers contain randomly generated numbers with 5-digits ranging from 1 to 9. No digits are
repeated. What is the probability that a randomly generated number is 54321?
8. MEETING Micah is arranging 15 chairs in a circle for an ice breaker game for the first club meeting. If people
choose their seats randomly, what is the probability Micah sits in the seat closest to the door?
Point L is chosen at random on ̅̅̅̅
𝑹𝑺. Find the probability of each event.
9. P(L is on ̅̅̅̅
𝑇𝑉 )
10. P(L is on ̅̅̅̅
𝑈𝑆)
Find the probability that a point chosen at random lies in the shaded region.
11.
12.
13.
14. PIGS Four pigs are lined up at the feeding trough as shown in
the picture. What is the probability that when a fifth pig comes to
eat it lines up between the second and third pig?
15. MUSIC A certain company plays Mozart’s Eine Kleine Nachtmusik when its customers are on hold on the telephone.
If the length of the complete recording is 2 hours long, what is the probability a customer put on hold will hear the
Allegro movement which is 6 minutes, 31 seconds long?