WorksheetsProbabilty
Total questions: 20
Worksheet time: 12mins
A die is rolled. The probability of getting an even number is:
0.5
0.25
0.8
0.54
If the probability of an event A is 0.7, then the probability of not A is:
0.5
0.3
1
0.7
The prior in Bayesian inference is defined as...
A) Evidence from data
B) Updated belief after seeing data
C) Initial belief before data
D) Marginal probability
Two dice are rolled together. The probability of getting a sum of 7 is:
1/6
1/12
1/18
1/36
A coin is tossed 3 times. The probability of getting at least one head is:
1/8
3/8
7/8
1/2
A card is drawn at random. The probability of getting a black king is:
1/26
1/52
1/13
1/12
If two events A and B are independent, then P(A∩B) equals:
P(A)+P(B)
P(A)−P(B)
P(A)×P(B)
P(A)/P(B)
A bag contains 3 red and 2 green balls. Two balls are drawn without replacement. The probability that both are red is:
3/10
2/10
1/5
6/10
The sum of probabilities of all possible outcomes of a random experiment is always:
0
0.5
1
Depends on the experiment
If a card is drawn at random, the probability of it being a face card (J, Q, K) is:
1/4
9/52
3/13
1/13
The probability of the union of two events A and B is given by:
P(A) + P(B)
P(A) + P(B) – P(A ∩ B)
P(A ∩ B)
P(A) × P(B)
If a card is drawn at random from a deck, what is P(getting a king | card is a face card)?
1/3
1/12
1/4
1/13
A bag contains 3 red and 5 black balls. One ball is drawn at random. If it is red, what is the probability of drawing another red ball in the second draw (without replacement)?
3/8
2/5
2/7
5/7
The posterior probability is...
A) Prior
B) Likelihood
C) P(A∣B) after observing B
D) Evidence
If P(A | B) = 1, then it means:
A always occurs without B
A never occurs with B
B ⊆ A (whenever B occurs, A occurs)
A and B are independent
Which of the following is correct?
P(A | B) = P(A) + P(B)
P(A | B) = P(A ∩ B) / P(B)
P(A | B) = P(B) / P(A)
P(A | B) = P(A) / P(B)
If P(A) = 0.3, P(B | A) = 0.5, and P(B | A′) = 0.2, then P(A | B) = ?
0.375
0.25
0.4
0.5
In a factory, 2 machines produce 60% and 40% of items respectively. Defective rates are 3% and 5%. If an item is defective, probability it came from Machine 1 is:
a) 0.36 b) 0.5 c) 0.72 d) 0.28
0.36
0.72
0.5
0.28
Which distribution is often used to model the number of events occurring in a fixed interval of time or space?
Normal
Poisson
Exponential
Binomial
In a Binomial distribution, the variance is given by:
n² × p
n × p × (1–p)
n × p
p × (1–p)
