Dependent or Independent
You roll a die and then flip a coin.
A) Are the following events independent or dependent?
B) What is the probability of rolling a 6 and flipping heads?
A) Independent
B) 1/6 * 1/2 = 1/12
At a local high school, 34% of the students take a bus to school and 56% of the students walk to school. What is the probability of randomly selecting a student that takes a bus or walks to school?
A) Are these events overlapping or disjoint?
B) Determine the probability of the event
A) Disjoint
B) 34/100 + 56/100 = 90/100
A bowl contains four apples, three bananas, three oranges. If a fruit is selected at random, what is the probability of selecting an orange?
3/10
the set of all possible outcomes of an event.
sample space
How many cards in a standard deck of 52 cards are red?
26
Marianna has a box of 6 red and 2 green marbles, she selects a marble doesn't replace and selects another.
A) Are these events dependent or independent?
B) Determine the probability of selecting a red marble then a green marble.
A) Dependent
B) 6/8 * 2/7 = 3/14
A card is drawn from a standard deck of cards. What is the probability of drawing a Jack or a Heart?
A) Are these events overlapping or disjoint?
B) Determine the probability of the event
A) Overlapping
B) 4/52 + 13/52 - 1/52 = 4/13
A bag contains 3 black, 5 green, and 4 yellow marbles.
What is the probability that a marble selected at random will be black?
3/12 or 1/4
The ratio of the number of favorable outcomes to the total number of outcomes.
Theoretical Probability
How many faces on a six-sided die are factors of 6? List them.
4
one, two, three, and six
You flip a coin three times in a row.
A) Are these events independent or dependent?
B) Find the probability of getting two heads
A) Independent
B) 1/2 * 1/2 * 1/2= 1/8
What is the probability of selecting a card from a standard deck of cards and the card is a 10 or an ace?
A) Are these events overlapping or disjoint?
B) Determine the probability of the event
A) disjoint
B) 4/52 + 4/52= 8/52 = 2/13
What is the probability of selecting a yellow or blue marble from a box of 5 green, 3 yellow, and 2 blue marbles?
5/10 or 1/2
The ratio of the number of favorable outcomes to the number of trials in an experiment.
Experimental Probability
Find the number of possible outcomes in the sample space when you roll a die and flip two coins.
24
Jack had 4 Snicker bars and 3 Mars bars. He randomly chose a piece of candy, ate it, then chose another.
A) Are these events Dependent or Independent?
B) What is the probability that both candy bars were snickers?
A) Dependent
B) 4/7 * 3/6= 12/42 or 2/7
On a spinner labeled with numbers 1-10, where each number is equally likely to be spun, determine the probability of spinning an odd number or a multiple of 3.
A) Are these events overlapping or disjoint?
B) Determine the probability of the event
A) Overlapping
B) 5/10 + 3/10 - 2/10 = 6/10 = 3/5
Shaquille shoots free throws at 50%. What is the probability of him making 2 free throws in a row?
1/4 or 25%
Events that can not happen at the same time are
disjoint or mutually exclusive
Find the number of possible outcomes in the sample space when you flip a coin and draw a marble from a bag containing two purple marbles and one white marble.
6
There are two traffic lights along the route that Ms. Prybella drives from home to work. One traffic light is red 50% of the time. The next traffic light is red 60% of the time. The lights operate on separate timers. Find the probability that these lights will both be red on Ms. Prybella's way home from work.
A) Are these events independent or dependent?
B) Determine the probability that both lights will be red
A) Independent
B) 50/100 * 60/100 = 3/10
On a school board, there are 10 members (4 female and 6 male). Two female members are over 40 years of age and 5 male members are over 40. If one person did not attend the meeting, what is the probability that the person was a male or a member over 40?
A) Are these events overlapping or disjoint?
B) Determine the probability of the event
A) Overlapping
B) P(male or over 40)= 6/10+ 7/10 - 5/10= 8/10 = 4/5
What is the probability of rolling two dice and getting a sum greater than 10
(5,6), (6,5), or (6,6)
3/36= 1/12
The sum of the probability of an event and the probability of the complement of the event is always
equal to 1 (one)
How many cards in a deck are black or a jack?
28