Online Test — Probability (Intro)
10 Questions • 20 min • Chapter MCQ
20:00
Question 1 of 10
easy
A bag has 4 red, 3 blue, 5 yellow marbles. Find P(red).
1/3
4/12
4/12 = 1/3
All of the above
Explanation: Total = 12. P(red) = 4/12 = 1/3. All three options express the same value.
Question 2 of 10
easy
Rolling a fair die: Find P(odd number).
1/6
1/3
1/2
2/3
Explanation: Odd numbers: 1, 3, 5 — that is 3 outcomes. P(odd) = 3/6 = 1/2.
Question 3 of 10
medium
A coin is flipped 200 times and lands heads 115 times. Find the experimental P(heads).
0.425
0.5
0.575
0.6
Explanation: Experimental P(heads) = 115/200 = 0.575
Question 4 of 10
medium
Spinner with 8 equal sections numbered 1-8. Find P(multiple of 3).
1/8
1/4
3/8
1/2
Explanation: Multiples of 3 from 1-8: 3 and 6 — that is 2 outcomes. P = 2/8 = 1/4.
Question 5 of 10
easy
P(impossible event) = ?
0
0.5
1
Undefined
Explanation: An impossible event can never occur, so its probability is 0.
Question 6 of 10
medium
A deck of 52 cards. Find P(face card: J, Q, or K).
3/13
4/13
12/52
Both A and C
Explanation: 12 face cards (J, Q, K in 4 suits). P = 12/52 = 3/13. Options A and C are equal.
Question 7 of 10
medium
Experimental probability of rolling a 6 on a die is 0.18 after 50 rolls. How many 6's were rolled?
6
7
8
9
Explanation: Number of 6's = 0.18 x 50 = 9
Question 8 of 10
medium
A spinner has Red (3 sections), Blue (2), Green (2), Yellow (1). Total 8 sections. Find P(not red).
3/8
1/2
5/8
3/4
Explanation: Not red = Blue+Green+Yellow = 2+2+1 = 5 sections. P(not red) = 5/8.
Question 9 of 10
medium
A die is rolled 120 times. How many times is a number less than 5 expected?
40
60
80
100
Explanation: P(less than 5) = 4/6 = 2/3. Expected = 120 x (2/3) = 80.
Question 10 of 10
medium
Which event has a theoretical probability of exactly 0.25?
Rolling a 6 on a die
Drawing a heart from a standard deck
Flipping tails on a coin
Spinning odd on a 1-8 spinner
Explanation: P(heart) = 13/52 = 1/4 = 0.25. The other events do not have this probability.