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Worksheetsprobability theory
Total questions: 145
Worksheet time: 5hrs 59mins
An event whose occurrence is impossible, is called
Sure event
Uncertain event
Null event
None of these
If the occurrence of one of them excludes the possibility of the occurrence of the other, then the event is called ...
Mutually exclusive/ Disjoint
Independent
Mutually exhaustive
Sure event
Number of combinations of 4 items taking 2 at a time, 4C2 =
5
6
0
4
If two events, A and B are mutually exclusive, then P(AUB) =
P(A) + P(B)
P(A) + P(B) - P(A ∩ B)
P(A) × P(B)
P(A)- P(B)
A card is selected from a deck of cards. What is the probability that the card is Black ?
521
131
21
41
Three coins are tossed simultaneously . The sample space will contain ... sample points.
1
2
4
8
Two Coins are tossed. Let X be the Random Variable indicating the number of Heads. X can take the values ...
0,1
0,1,2
0,1,2,3
0,1,2,3,4
Two Dice are tossed. What is the probability of getting sum of the numbers on the dice is 3
361
181
363
183
The probability P(A/B) is called ....
Independent probability
Disjoint Events
Sure Probability
Conditional Probability
How many 2 digit numbers can be formed using the digits of the number 6789 if repetition of numbers are not allowed ( 66, 77, 88 & 99 not allowed)?
16
12
6
8
How many 2 digit numbers can be formed using the digits of the number 6789 if repetition of numbers are allowed ( 66, 77, 88 & 99 are allowed)?
16
12
6
8
find P(A∪B). when P(A)=0.3, P(B)=0.4, A and B are Mutually exclusive events.
0.3
0.4
0.7
0.58
find P(A∪B). when P(A)=0.3, P(B)=0.4, A and B are indendent events.
0.3
0.4
0.7
0.58
P(A∪B)=0.6 , P(A)=0.5 , P(B)=0.2 find P(A∩B)
0
0.2
0.1
0.7
P(Atleast One )= 65 find P( No One).
65
61
32
56
C−Student of Commerce Dept. E− Students of Economics Dept. B −Boys of Our college Then E∩C= ?
ϕ
E−C
E∪C
E⊂C
P(A)= Total Casesfavourable Cases , This definition of probability is called ...
Axiomatic Definition
Classical Definition
Frequency Definition
Subjective Definition
What is the probability of having 53 Sundays in a leap year ?
3661
531
71
72
When a die is thrown, ...................is the probability of getting a 5
61
65
21
54
Two events are said to be independent if
There is no common point in between them
Both the events have only one point
Each outcome has equal chance of occurrence
One does not affect the occurrence of the other
Sample space for the event of tossing two coins is
S={1,2,3,4,5,6}
S={H,T}
S={HH, HT, TH, TT}
S={HHH,HHT,HTH,HTT,THT,TTH,THH,TTT}
P(A∩B)≤P(A)
True
False
in Some Cases, P(A) can take negative values
True
False
P(A)=1.25. is this possible for an event A ?
Yes, its Possible
No, P(A) cannot take a value geater than one
Here the events A, B are called...
Sure Events
Null Events
Disjoint Events
Mutual Events
A die is numbered as 1,2,3,4,5,6 on the faces. When this die is thrown the sample space is S = {1,2,3,4,5,6}
True
False
a
b
c
d
a
b
c
The probability of drawing a spade from a pack of 52 cards is
521
31
41
134
(i) and (ii) are true
(i) is true and (ii) is false
(i) is false and (ii) is true
(i) and (ii) are false
Two coins are tossed simultaneously, the probability of getting a head and a tail is
1/2
1/6
1/4
1/3
a
b
c
d
a
b
c
d
a
b
c
Pairwise independence of n events ⇒ independence of n events
True
False
If F(x) is a distribution function of the random variable X and if a < b then P(a < X ≤ b) is
P(a)
P(b)
F(b) - F(a)
F(a) - F(b)
If X is a continuous random variable, the probability of every set consisting of a single point is
zero
one
infinity
A random variable X is a discrete random variable if it takes at most ______________values.
a countable number of values
an infinite number of values
a countable or infinite number of values
Choose the correct option by reading the statements about Mathematical expectation
(i) E(c)=c is where is a constant
(ii) E(c X) = c E(X) where c is a constant
(ⅲ)E(X+Y) =E(X). E(Y) (ⅳ) E(XY)=E(X)+E(Y)
All the four statements are true
Only (iii) and (iv) are true
Only (i) and (ii) are true
All the four statements are false
The concept of _____________arises when we deal with variables like heights, weights, temperature which can take any value between certain limits.
discrete random variable
continuous random variable
experiment
probability
True
False
Any subset A of a sample space S is called
an event
sample points
experiment
exhaustive
If A and B are two events with P (A) = 0.4, P (B) = 0.3 and P (A∩B) = 0.2. Find P (A∪B)
0.5
0.8
0.1
0.2
Two dice numbered as 1,2, ……,6 on their faces are thrown. Let A be the event that the sum of the numbers on the faces shown is odd and B be the event that at least one number is 1. Then P (A ∩ B)
1/2
1/6
1/3
1/4
Two dice numbered as 1,2, ……,6 on their faces are thrown. Let A be the event that the sum of the numbers on the faces shown is odd and B be the event that at least one number is 1. Then P (AυB)
23/36
29/36
5/6
11/72
*Remember to simplify.*
What is the probability the spinner stops on yellow?
.075
50%
25%
3/8
A box has 3 limes, 5 grapes, and 2 oranges.
P (not lime)
3/10
30%
7/10
Answer Not Here
Marvin has a standard deck of cards.
(52 in a deck, 4 suits)
P (Ace or a 5)
1/13
2/13
1/26
8/50
Amelia receives a treat bag. The treat bag contains 10 gumballs, 5 pixie sticks, 2 bracelets, and 3 chocolates. If Amelia selects 3 items from her treat bag without looking and gives them to her sister, which could NOT represent a possible outcome for the items Amelia selects?
gumball, gumball, gumball
pixie stick, gumball, chocolate
bracelet, bracelet, bracelet
gumball, gumball, pixie stick
The list shows all possible outcomes for which experiment?
S = { (heads, heads), (heads, tails),
(tails, tails), (tails, heads) }
Flipping a coin one time
Flipping a coin two times
Flipping a coin three times
Flipping a coin four times
Which of the following are possible samples spaces for tossing 2 coins? (May be more than one correct answer)
{H, T, H, T}
{HH, HT, TH, TT}
{H, T}
{T, H}
{TT, HH, TH, HT}
Which of the following shows or illustrates MUTUALLY EXCLUSIVE EVENTS?
Getting a diamond card or spade card in a deck of cards
Getting a face card or an ace in a deck of cards
Getting an ace and a red card in a deck of cards
Getting a heart or a face card
Which of the following shows or illustrates INCLUSIVE EVENTS?
Getting a diamond card or spade card in a deck of cards
Getting a face card or an ace in a deck of cards
Getting an ace and a red card in a deck of cards
Getting a heart or a face card
Which of the following shows or illustrates MUTUALLY EXCLUSIVE EVENTS?
Getting an even number or an odd number in rolling a die
Getting 4 or a number greater than 2 in rolling a die
Getting 1 or a number less than 3 in rolling a die
Getting a heart or a face card
In a room with 28 people, there are 5 women wearing red and 7 wearing blue, and there are 6 men wearing red and 10 men wearing purple. What is the probability of randomly picking one person who is either wearing red or is a male?
2811
2816
143
43
Find the probability of drawing an ace or a red card in a standard deck of 52 cards.
131
21
261
137
The table above shows the number of cell phones per household in a small town. Find the standard deviation. Round to the nearest hundredth.
0.80
1.70
1.30
1.00
X 0 1 2 3 4 5
P(X) 0.24 0.37 0.20 0.11 0.05 0.03
What is the probability that a randomly chosen household has at least two cars?
If two coins are tossed, which is NOT a possible value of the random variable for the number of heads?
0
1
2
3
By using Binomial/ Poisson Statistical Table P(X≥r) , how to find P(X≤14) ?
1−P(X≥15)
1−P(X≤15)
1−P(X≥14)
1−P(X≤14)
Find mean of Binomial Distribution?
np
npq
nq
1-q
If the values of the random variable X are 0,1,2 and 3 where X represents the number of heads in tossing a coin thrice, what is the probability that three heads will come up?
1/2
3/8
1/4
1/8
Which of the following is NOT a requirement of a discrete probability distribution?
The sum of the values for the random variable x must add up to 1.
There is a discrete numerical (not categorical) random variable x, and its number values are associated with corresponding probabilities.
The sum of the probabilities must all add up to 1.
Every individual probability must have a value between 0 and 1 inclusively.
An algebra 2 test has 6 multiple choice questions with four choices with one correct answer each. If we just randomly guess on each of the 6 questions, what is the probability that you get exactly 3 questions correct?
0.962
0.132
0.831
0.250
Suppose we draw 4 cards from a pack of 52 cards. What is the probability of getting exactly 3 kings?
0.9999
0.9997
0.0007
The mean number of accidents per month at a certain intersection is 3.What is the probability that in any given month exactly 4 accidents will occur at this intersection?
0.081
0.672
0.168
If A and B are any two events of a sample space S, then
P (A ∪ B) = P (A) + P (B) – P (A ∩ B)
P (A ∪ B) = P (A) + P (B) + P (A ∩ B)
P (A ∩ B) = P (A) + P (B) +P (A ∪ B)
P (A / B) = P (A) - P (B) – P (A ∩ B)
1. If A and B are disjoint events P (A ∪ B) = __________.
P (A) + P (B)
P (A) – P (B)
P (A) P(B)
P (A) + P (A ∩ B)
1. If A and B are events of a sample space S such that A ⊆ B then
P (A) = P (B)
P (A) < P (B)
P (A) ≤ P (B)
P (A) = P (B)
1. If A and B are two events with P (A) = 0.4, P (B) = 0.3 and P (A ∩ B) = 0.2. Find P (A ∪ B)
0.5
0.8
0.1
0.2
If Ai∩Aj = ϕ for all i, j with i ≠ j then the sequence of subsets is said to be __________.
Mutually disjoint
Exhaustive
Independent
not Independent
1. Two dice numbered as 1,2, ……,6 on their faces are thrown. Let A be the event that the sum of the numbers on the faces shown is odd and B be the event that at least one number is 1. Then P (A ∩ B) = __________.
1/2
1/3
1/6
2/6
Two dice numbered as 1,2, ……,6 on their faces are thrown. Let A be the event that the sum of the numbers on the faces shown is odd and B be the event that at least one number is 1. Then P (A ∪ B) = __________.
25/26
23/26
29/26
5/6
Let A and B be two events with P (B) ≠ 0. A is said to be independent of
B if P (A|B) = __________.
P (A)
P (A) P (B)
P (B)
P (A ∪ B)
Say True or False.
If A and B are independent events then A and are also independent.
True
False
If A, B, C are mutually independent events then
A ∪ B and B ∪ C are independent
A ∩ B and A ∩ C are independent
A and B ∩ C are independent
A ∪ B and C are independent
If F(x) is a distribution function of the random variable X and if a<b then P(a<X≤b) is
P(a)
P(b)
F(b) - F(a)
F(a) - F(b)
Mathematical expectation is also called as
variance of a random variable (discrete only)
variance of a random variable (continuous only)
standard deviation of a random variable (continuous only)
mean of a random variable (discrete or continuous)
If a random variable takes countable number of values x₁, x₂, ….xₙ… it is called as (a) .
Mathematical expectation is
absolutely divergent
absolutely convergent
convergent
divergent
Say True or False.
Let X be a continuous random variable taking the values in the interval (-∞, ∞). Let f(x) be a function then ∫−∞∞f(x) = 0
True
False
If X is a continuous random variable, the probability of every set consisting of a single point is
0
1
∞
−∞
The probability density function of the continuous random variable X is got by __________________ the distribution function F(x) of X.
adding
differentiating
integrating
subtracting
Choose the correct option by reading the statements about Mathematical expectation
(i) E(c)=c is where is a constant (ii) E(c X) = c E(X) where c is a constant
(ⅲ)E(X+Y) =E(X). E(Y) (ⅳ) E(XY)=E(X)+E(Y)
All the four statements are true
Only (iii) and (iv) are true.
Only (i) and (ii) are true.
All the four statements are false.
The concept of _____________arises when we deal with variables like heights, weights, temperature which can take any value between certain limits.
continuous random variable
discrete random variable
A random variable X is said to be a continuous random variable if it can take any value in an interval which may be _______________ or ________________.
(a)
If X is a Poisson variable with P(X=3) = P(X=4) then P(X=0) is...........
0.183
0.0183
0.00183
1.0183
Say true or false : MX= -a (t) = eat MX (t) .
True
False
If X is a Poisson variate with P( X = 0) = P (X = 1) = c, then the value of c is
e
-e
1/e
-1/e
Variance of the Poisson distribution is ...........
1/λ
λ2
1/ λ2
λ
M.g.f. of Poisson distribution about the origin is --------
eλ(et−1−t)
eλ(eit−1)
eλ(et−1)
eλ(eit−1−t)
The mean of the Poisson distribution whose p.d.f is P(x) = x!e−(0.5)(0.5)x is ………..
- 0.5
-0.05
0.5
0.05
If X is a Poisson variate with parameter 1, P( 3 < X < 5 ) = …………..
0.0153
0.0183
0.0163
0.0172
If the mean and variance of a Binomial distribution are 4 and 8/3 respectively,
then its mode is
4.3
3
3.4
4
M.g.f of a binomial distribution about the origin is …….
(p+qet)n
(p+qeit)n
(q+pet)n
(p+q)n
M.g.f about the mean np of a binomial distribution is………………
(qe−pt+peqt)n
(qept+pe−qt)n
(qe−t+pet)n
(qe−pt+peqt)
The mode of a binomial distribution B( 7, 1/4) is ……….
1
2
1 and 2
2 and 3
If the m.g.f of a random variable X is of the form MX(t) = (0.4et+0.6)8 then
E(X) = ……………
3
3.1
3.2
3.3
If the probability of defective bolt is 1/10 then the coefficient of skewness based
on moments is ........
0.018
0.18
0.81
0.081
The Characteristic function of binomial distribution = …………
(q+pet)n
(q+peit)n
(p+qeit)n
(q+pe−it)n
Find the first three moments of the binomial distribution
1.68, 4.2, 0.336
4.2, 1.68, -0.336
0.336, 4.2, 1.68
0, 1.68, -0.336
M.g.f about the origin of the normal distribution is ............
eμt+2(t2σ2)
eμt+(t2σ2)
e2(t2σ2)
e2t2
For the normal distribution, μ2n+1 = ----- for n = 1,2,….
1
1/2
-1
0
In a normal distribution, the value of β2 is given by
0
3
2
1
The mean and standard deviation of the normal distribution f(x) = Ke−(21)[4(x2+8x+16)]
are respectively
-4, 2
-4, 4
-4, 2
4, −2
Say true or false:
All the even order moments about mean of the normal distribution is zero.
True
False
While Tim is waiting for class to start, he pulls a quarter from his pocket. How many outcomes are possible if he flips the quarter 3 times?
3
6
12
8
What is the probability of getting an odd number on the first roll and less than 3 on the second roll?
1/6
2/6
3/5
3/6
Based on the chart, what is the experimental probability of pulling a green marble?
1/8
8/25
8/100
7/8
A spinner has 8 equal regions. Each region is marked with one of the following numbers: 10, 20, 30, 40, 50, 60, 70, 80. What is the probability of an even number being spun on the first roll?
1/8
1/2
1
3/8
Kevin is making an omelet. There are 7 types of meat and 2 types of cheese to choose from. How many different omelets can Kevin make using exactly one of each item?
7
14
9
24
Alvin rolls a fair 6-sided die.
What is P(roll greater than 6)?
(a)
Let X and Y be the following sets:
P(X) = {5, 10, 15}
P(Y) = {3, 6, 9, 12, 15}
Which of the following is the set X U Y?
{5, 10, 15}
{3, 6, 9, 12, 15}
{}
{3, 5, 6, 9, 10, 12, 15}
Let X and Y be the following sets:
X = {121, 144, 169}
Y = {11, 12, 13, 121, 144, 169}
Which of the following is the set X ∩ Y?
{121, 144,169}
{11, 12, 13, 121, 144, 169}
{}
{11, 12, 13}
Three events occur with probabilities P(E1) = 0.35, P(E2) = 0.15, P(E3) = 0.40. If the event B occurs, the probability becomes P(E1|B) = 0.25, P(B) = 0.30. Calculate P(E1 or B).
0.075
0.575
0.021
0.475
Drake Marketing and Promotions has randomly surveyed 200 men who watch professional sports. The men were separated according to their educational level (college degree or not) and whether they prefer the NBA or the National Football League (NFL). The results of the survey are shown:
What is the probability that a randomly selected participant prefers NFL?
(a)
A bag has 2 black and 3 red marbles. You reach into the bag, select a marble and then replace it. What is P(red, then red)?
9/25
1/9
3/10
1/72
The probability model based on experimental probability for randomly selecting a marble from a bag is P(green) = 4018 , P(blue) = 4014 , and P(white) = 408 . If there are 60 total marbles in the bag, how many would you expect to be white?
(a)
The results of a survey asking 500 people about their favorite ice cream flavor are shown in the table. Find P(strawberry) as a percentage.
(a)
You spin each spinner once. You get $50 if you spin a 2 and a vowel. You get $25 if you spin a 2 and a consonant. You get $5 if you spin a 1 and a vowel. Everything else earns $0. What is the expected value of this game?
$80
$8.75
$10.25
$12.50
Your business is looking into looking into three contracting firms. Based on previous research, there is a 75% chance that company 1 will earn you $40,000. There is a 45% chance that company 2 will earn you $60,000. Company 3 has a 30% chance of earning you $80,000. It costs $20,000 to draw up legal paperwork for each company. How much profit or loss would you expect after this deal is done?
$81,000 profit
$81,000 loss
$21,000 profit
$21,000 loss
Kevin is at a charity fundraiser and has a chance of receiving a gift. The odds in favor of receiving a gift are 6/17. Find the probability of Kevin receiving a gift.
6/23
17/23
17/6
23/6
