Probability Test for Data Science (Free Online MCQs)

1. The probability of an event that cannot occur is:

• (a) 0
• (b) 1
• (c) 0.5
• (d) Undefined

2. The probability of an event that is certain to happen is:

• (a) 0
• (b) 1
• (c) 0.5
• (d) Depends on experiment

3. When rolling a fair six-sided die, the probability of getting 5 is:

• (a) 1/3
• (b) 1/6
• (c) 1/2
• (d) 5/6

4. Probability of getting a head when tossing a fair coin is:

• (a) 0
• (b) 0.5
• (c) 1
• (d) 2

5. Two events A and B are independent if:

• (a) P(A ∩ B) = P(A) + P(B)
• (b) P(A ∩ B) = P(A)P(B)
• (c) P(A ∪ B) = P(A) + P(B)
• (d) P(A ∪ B) = P(A)P(B)

6. The sum of probabilities of all possible outcomes in an experiment is:

• (a) Less than 1
• (b) 1
• (c) Greater than 1
• (d) Undefined

7. The probability of at least one head in two coin tosses is:

• (a) 1/4
• (b) 1/2
• (c) 3/4
• (d) 1

8. If P(A) = 0.6, P(B) = 0.5, and P(A ∩ B) = 0.3, the events are:

• (a) Independent
• (b) Mutually exclusive
• (c) Dependent
• (d) Complementary

9. Probability of getting a 2 or a 5 when rolling a die is:

• (a) 1/6
• (b) 2/6
• (c) 1/3
• (d) 1/2

10. Probability of the complement of an event A is:

• (a) P(A)
• (b) 1 − P(A)
• (c) 1 + P(A)
• (d) −P(A)

11. Probability of getting two heads in two coin tosses is:

• (a) 1/4
• (b) 1/2
• (c) 1/3
• (d) 1

12. If two events are mutually exclusive, then P(A ∪ B) =

• (a) P(A)P(B)
• (b) P(A) + P(B)
• (c) P(A) − P(B)
• (d) 1 − P(A)P(B)

13. The sample space of tossing a coin twice is:

• (a) {H, T}
• (b) {HH, HT, TH, TT}
• (c) {H, H, T, T}
• (d) {0,1,2}

14. The sum of probabilities of mutually exclusive events A and B is:

• (a) Less than 1
• (b) Equal to 1
• (c) Equal to 0
• (d) Greater than 1

15. Conditional probability P(A|B) is defined as:

• (a) P(A ∩ B) / P(B)
• (b) P(A) / P(B)
• (c) P(B ∩ A) / P(A)
• (d) P(A) + P(B)