Mixed
One letter is selected at random from the word "UNNECESSARY."
This is the probability of selecting an R or and E.
What is 3/11?
Given that P(A)=0.3, P(B)=0.4 and P(A U B)=0.65,
This is P(A l B).
What is 0.125 or 1/8?
A group of 30 cats were given two different types of food. 7 cats liked only food A, 5 cats liked only food B, 16 liked both and 2 liked neither.
This is the probability that a randomly selected cat liked both foods A and B.
What is 8/15?
The probability that an archer hits a target when he shoots an arrow is 0.7. The archer shoots two arrows at a target.
This is the probability that at least one arrow hits the target.
What is 0.91?
An unbiased spinner is numbered 1, 2, 2, 3, 3, 3. The spinner is spun several times until it lands a 2.
This is the probability that this happened on the fifth spin.
What is 16/243?
Given that P(A)=0.8, P(B)=0.7 and P(A ∩ B)=0.5,
This is P(A l B').
What is 1.
In a school of 90 learners, 47 study Maths and 57 study English. Twelve learners study neither subject. Zahra pick an English learner at random.
This is the probability that she picked someone who also study Maths.
What is 26/57?
The probability that Robert will pass his driving test on his first attempt is 2/3. If he fails, the probability that he passes on any future attempt is 3/4.
This is the probability that he passes on his fifth attempt.
What is 1/256?
A bag contains 3 red, 4 white and 5 green balls. Three balls are selected without replacement. The selection of the was carried out 1100 times.
This is expected number of times that the 3 balls has one of each colour.
What is 300?
Let E and F are events of a experiment such that P(E) = 3/10 P(F) = ½ and P(F|E) = ⅖.
This is P(E ∩ F).
What is 3/25?
A play is being performed twice; first on a Friday and again on a Saturday. 100 people who wanted to see the play were asked which of the performances they could attend. 58 people said they could attend the Friday performance, 74 said they could attend the Saturday performance, and 4 said they could attend neither.
This is the probability that a randomly selected person could attend either performance.
What is 36/100?
A bag contains 3 red and 7 black balls. Two balls are drawn at random without replacement.
The second ball is red. This is the probability that the first ball is also red.
What is 2/9?
Bag A contains 3 red balls and 3 blue balls. Bag B contains 1 red ball and 3 blue balls. A ball is taken at random from B and placed in bag B. A ball is then chosen from Bag B.
This is the probability that the ball taken from B is red.
What is 3/10?
If P(A) = 3/4 P(B) = 5/8 and P(A|B) = 4/5,
This is the value of P(A U B).
What is 7/8?
Of the students who took English in a certain school one year, 60% of them took History, 30% of them took Biology, and 10% took both History and Biology. One of the students taking English is chosen at random.
This is the probability he/she was taking History, given that the student took exactly one of History and Biology.
What is 5/7?
Walker's disease is a rare tropical disease, known to be present in only 0.1% of the population. A new screening test has been analysed, and there is a 98% probability of testing positive when the person tested has the disease, and only 0.2% probability of testing positive when the person does not have the disease.
This is the probability (in 3 sf) that the person does not have the disease, given that they test positive.
What is 0.671?
Box A contains 4 black balls and 1 white ball. Box B contains B contains 4 black balls and 3 white balls. Amir is asked to choose 2 balls at random from A or 2 balls at random from B. He does not replace the first ball before choosing the second ball. The probability that he chooses from A is 5/8.
This is the probability that Amir chooses two different coloured balls.
What is 13/28?
Three bags that each contain 100 marbles:
The chosen marble is red.
This is the probability that Bag 1 was chosen.
Probability that a red ball was taken from Bag 1 = 0.75
Probability that Bag 1 is chosen = 1/3
Probability that a red ball is chosen from 3 bags = 3/5
[P(red ball is taken from Bag 1)*P(Bag 1)]/P(red ball)
What is 5/12?
A play is being performed twice; first on a Friday and again on a Saturday. 100 people who wanted to see the play were asked which of the performances they could attend. 58 people said they could attend the Friday performance, 74 said they could attend the Saturday performance, and 4 said they could attend neither.
If one customer who wanted a ticket for the Saturday performance accidentally bought a ticket for the Friday performance, what is the probability that they would still be able to go?
What is 36/58?
In my town, it's rainy one third of the days. Given that it is rainy, there will be heavy traffic with probability 1/2, and given that it is not rainy, there will be heavy traffic with probability 1/4. If it's rainy and there is heavy traffic, I arrive late for work with probability 1/2. On the other hand, the probability of being late is reduced to 1/8 if it is not rainy and there is no heavy traffic. In other situations (rainy and no traffic, not rainy and traffic) the probability of being late is 0.25. You pick a random day.
Given that I arrived late at work, what is the probability that it rained that day?
Probability of being late = 11/48
Probability of being late when it is raining = 1/8
What is 6/11?