LFM Stats And Pure

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csat-suneung 2011 Q7 3 marks Probability Using Set/Event Algebra View
A student named Chulsu participated in a design competition. Participants receive scores in two categories, and the possible scores in each category are one of three types shown in the table. The probability that Chulsu receives score A in each category is $\frac { 1 } { 2 }$, the probability of receiving score B is $\frac { 1 } { 3 }$, and the probability of receiving score C is $\frac { 1 } { 6 }$. When the event of receiving audience voting scores and the event of receiving judge scores are mutually independent, what is the probability that the sum of the two scores Chulsu receives is 70? [3 points]
CategoryScore AScore BScore C
Audience Voting403020
Judges504030

(1) $\frac { 1 } { 3 }$
(2) $\frac { 11 } { 36 }$
(3) $\frac { 5 } { 18 }$
(4) $\frac { 1 } { 4 }$
(5) $\frac { 2 } { 9 }$
csat-suneung 2011 Q7 3 marks Probability Using Set/Event Algebra View
Chulsu participated in a certain design competition. Participants receive scores in two categories, and the possible scores in each category are one of three types shown in the table. The probability that Chulsu receives score A in each category is $\frac { 1 } { 2 }$, the probability of receiving score B is $\frac { 1 } { 3 }$, and the probability of receiving score C is $\frac { 1 } { 6 }$. When the event of receiving an audience vote score and the event of receiving a judge score are independent, what is the probability that the sum of the two scores Chulsu receives is 70? [3 points]
CategoryScore AScore BScore C
Audience Vote403020
Judge504030

(1) $\frac { 1 } { 3 }$
(2) $\frac { 11 } { 36 }$
(3) $\frac { 5 } { 18 }$
(4) $\frac { 1 } { 4 }$
(5) $\frac { 2 } { 9 }$
csat-suneung 2012 Q13 3 marks Conditional Probability and Bayes' Theorem View
Box A contains 3 red balls and 5 black balls, and box B is empty. When 2 balls are randomly drawn from box A, if a red ball appears, perform [Execution 1], and if no red ball appears, perform [Execution 2]. What is the probability that the number of red balls in box B is 1? [3 points] [Execution 1] Put the drawn balls into box B. [Execution 2] Put the drawn balls into box B, and then randomly draw 2 more balls from box A and put them into box B.
(1) $\frac { 1 } { 2 }$
(2) $\frac { 7 } { 12 }$
(3) $\frac { 2 } { 3 }$
(4) $\frac { 3 } { 4 }$
(5) $\frac { 5 } { 6 }$
csat-suneung 2014 Q15 4 marks Conditional Probability and Bayes' Theorem View
Bag A contains 2 white balls and 3 black balls, and Bag B contains 1 white ball and 3 black balls. One ball is randomly drawn from Bag A. If it is white, 2 white balls are put into Bag B; if it is black, 2 black balls are put into Bag B. Then one ball is randomly drawn from Bag B. What is the probability that the drawn ball is white? [4 points]
(1) $\frac { 1 } { 6 }$
(2) $\frac { 1 } { 5 }$
(3) $\frac { 7 } { 30 }$
(4) $\frac { 4 } { 15 }$
(5) $\frac { 3 } { 10 }$
csat-suneung 2015 Q8 3 marks Probability Using Set/Event Algebra View
For two events $A , B$, $A ^ { C }$ and $B$ are mutually exclusive events, and $$\mathrm { P } ( A ) = 2 \mathrm { P } ( B ) = \frac { 3 } { 5 }$$ When this condition is satisfied, what is the value of $\mathrm { P } \left( A \cap B ^ { C } \right)$? (Here, $A ^ { C }$ is the complement of $A$.) [3 points]
(1) $\frac { 3 } { 20 }$
(2) $\frac { 1 } { 5 }$
(3) $\frac { 1 } { 4 }$
(4) $\frac { 3 } { 10 }$
(5) $\frac { 7 } { 20 }$
csat-suneung 2017 Q3 2 marks Set Operations View
Two sets $$A = \{ 1,2,3,4,5 \} , B = \{ 2,4,6,8,10 \}$$ What is the value of $n ( A \cup B )$? [2 points]
(1) 6
(2) 7
(3) 8
(4) 9
(5) 10
csat-suneung 2017 Q4 3 marks Probability Using Set/Event Algebra View
For two events $A$ and $B$, $$\mathrm { P } ( A \cap B ) = \frac { 1 } { 8 } , \mathrm { P } \left( A \cap B ^ { C } \right) = \frac { 3 } { 16 }$$ What is the value of $\mathrm { P } ( A )$? (Here, $B ^ { C }$ is the complement of $B$.) [3 points]
(1) $\frac { 3 } { 16 }$
(2) $\frac { 7 } { 32 }$
(3) $\frac { 1 } { 4 }$
(4) $\frac { 9 } { 32 }$
(5) $\frac { 5 } { 16 }$
csat-suneung 2017 Q13 3 marks Finite Equally-Likely Probability Computation View
The total number of students at a certain school is 360, and each student chose either experiential learning A or experiential learning B. Among the students at this school, those who chose experiential learning A are 90 male students and 70 female students. When one student is randomly selected from the students at this school who chose experiential learning B, the probability that this student is male is $\frac { 2 } { 5 }$. What is the number of female students at this school? [3 points]
(1) 180
(2) 185
(3) 190
(4) 195
(5) 200
csat-suneung 2017 Q26 4 marks Finite Equally-Likely Probability Computation View
There are two bags A and B, each containing 4 cards with the numbers $1,2,3,4$ written on them. Person 甲 draws two cards from bag A, and person 乙 draws two cards from bag B, each randomly. The probability that the sum of the numbers on the two cards held by 甲 equals the sum of the numbers on the two cards held by 乙 is $\frac { q } { p }$. Find the value of $p + q$. (Here, $p , q$ are coprime natural numbers.) [4 points]
csat-suneung 2018 Q3 2 marks Set Operations View
Two sets $A = \{ 2 , a + 1,5 \} , B = \{ 2,3 , b \}$ satisfy $A = B$. Find the value of $a + b$. (Here, $a$ and $b$ are real numbers.) [2 points]
(1) 4
(2) 5
(3) 6
(4) 7
(5) 8
csat-suneung 2019 Q2 2 marks Set Operations View
Two sets $$A = \{ 3,5,7,9 \} , B = \{ 3,7 \}$$ For the sets above, when $A - B = \{ a , 9 \}$, what is the value of $a$? [2 points]
(1) 1
(2) 2
(3) 3
(4) 4
(5) 5
csat-suneung 2019 Q10 3 marks Probability Involving Algebraic or Number-Theoretic Conditions View
A bag contains 7 marbles, each labeled with a natural number from 2 to 8. When 2 marbles are drawn simultaneously from the bag, what is the probability that the two natural numbers on the drawn marbles are coprime? [3 points]
(1) $\frac { 8 } { 21 }$
(2) $\frac { 10 } { 21 }$
(3) $\frac { 4 } { 7 }$
(4) $\frac { 2 } { 3 }$
(5) $\frac { 16 } { 21 }$
csat-suneung 2021 Q8 3 marks Finite Equally-Likely Probability Computation View
A die is rolled three times, and the results are $a$, $b$, and $c$ in order. What is the probability that $a \times b \times c = 4$? [3 points]
(1) $\frac { 1 } { 54 }$
(2) $\frac { 1 } { 36 }$
(3) $\frac { 1 } { 27 }$
(4) $\frac { 5 } { 108 }$
(5) $\frac { 1 } { 18 }$
csat-suneung 2021 Q9 3 marks Finite Equally-Likely Probability Computation View
There are 5 cards with letters $\mathrm { A } , \mathrm { B } , \mathrm { C } , \mathrm { D } , \mathrm { E }$ written on them and 4 cards with numbers $1,2,3,4$ written on them. When all 9 cards are arranged in a line in random order using each card once, what is the probability that the card with letter A has number cards on both sides? [3 points]
(1) $\frac { 5 } { 12 }$
(2) $\frac { 1 } { 3 }$
(3) $\frac { 1 } { 4 }$
(4) $\frac { 1 } { 6 }$
(5) $\frac { 1 } { 12 }$
csat-suneung 2023 Q25 3 marks Probability Using Set/Event Algebra View
A box contains 5 white masks and 9 black masks. When 3 masks are randomly drawn simultaneously from the box, what is the probability that at least one of the 3 masks is white? [3 points]
(1) $\frac { 8 } { 13 }$
(2) $\frac { 17 } { 26 }$
(3) $\frac { 9 } { 13 }$
(4) $\frac { 19 } { 26 }$
(5) $\frac { 10 } { 13 }$
gaokao 2015 Q1 5 marks Set Operations View
Given sets $A = \{ 1,2,3 \} , B = \{ 1,3 \}$, then $\mathrm { A } \cap \mathrm { B } =$
(A) $\{ 2 \}$
(B) $\{ 1,2 \}$
(C) $\{ 1,3 \}$
(D) $\{ 1,2,3 \}$
gaokao 2015 Q1 Set Operations View
1. Given sets $A = \{ 1,2,3 \} , B = \{ 2,4,5 \}$, then the number of elements in set $A \cup B$ is $\_\_\_\_$ .
gaokao 2015 Q1 5 marks Set Operations View
Given sets $\mathrm { A } = \{ - 2 , - 1,0,2 \} , \mathrm { B } = \{ \mathrm { x } \mid ( \mathrm { x } - 1 ) ( \mathrm { x } + 2 ) < 0 \}$ , then $\mathrm { A } \cap \mathrm { B } =$
(A) $\{ - 1,0 \}$
(B) $\{ 0,1 \}$
(C) $\{ - 1,0,1 \}$
(D) $\{ 0,1,2 \}$
gaokao 2015 Q1 Set Operations View
1. Let $M = \left\{ x \mid x ^ { 2 } = x \right\} , N = \{ x \mid \lg x \leq 0 \}$, then $M \bigcup N =$
A. $[ 0,1 ]$
B. $( 0,1 ]$
C. $[ 0,1 )$
D. $( - \infty , 1 ]$
gaokao 2015 Q1 5 marks Set Operations View
Given the universal set $U = \{1,2,3,4,5,6,7,8\}$, set $A = \{2,3,5,6\}$, set $\mathrm{B} = \{1,3,4,6,7\}$, then $\mathrm{A} \cap \mathrm{C}_{U}\mathrm{B} =$
(A) $\{2,5\}$
(B) $\{3,6\}$
(C) $\{2,5,6\}$
(D) $\{2,3,5,6,8\}$
gaokao 2015 Q3 Set Operations View
3. The negation of the proposition ``$\exists x _ { 0 } \in ( 0 , + \infty ) , \ln x _ { 0 } = x _ { 0 } - 1$'' is
A. $\forall x \in ( 0 , + \infty ) , \ln x \neq x - 1$
B. $\forall x \notin ( 0 , + \infty ) , \ln x = x - 1$
C. $\exists x _ { 0 } \in ( 0 , + \infty ) , \ln x _ { 0 } \neq x _ { 0 } - 1$
D. $\exists x _ { 0 } \notin ( 0 , + \infty ) , \ln x _ { 0 } = x _ { 0 } - 1$
gaokao 2015 Q5 Finite Equally-Likely Probability Computation View
5. A bag contains 4 balls of identical shape and size, including 1 white ball, 1 red ball, and 2 yellow balls. If 2 balls are randomly drawn at once, then the probability that the 2 balls have different colors is $\_\_\_\_$ .
gaokao 2015 Q11 Set Operations View
11. Given the set $\mathrm { U } = \{ 1,2,3,4 \} , \mathrm { A } = \{ 1,3 \} , \mathrm { B } = \{ 1,3,4 \}$, then $\mathrm { A } \cup ( C \cup B ) =$ $\_\_\_\_$
gaokao 2015 Q16 Finite Equally-Likely Probability Computation View
16. (This question is worth 12 points)
A shopping mall is holding a promotional lottery activity. After customers purchase goods of a certain amount, they can participate in the lottery. The lottery method is as follows: randomly draw 1 ball each from box A containing 2 red balls $\mathrm { A } _ { 1 } , \mathrm { A } _ { 2 }$ and 1 white ball B, and from box B containing 2 red balls $\mathrm { a } _ { 1 } , \mathrm { a } _ { 2 }$ and 2 white balls $\mathrm { b } _ { 1 } , \mathrm { b } _ { 2 }$. If both balls drawn are red, the customer wins; otherwise, the customer does not win. (I) List all possible outcomes of drawing balls using the ball labels. (II) Someone claims: Since there are more red balls than white balls in both boxes, the probability of winning is greater than the probability of not winning. Do you agree? Please explain your reasoning.
gaokao 2015 Q17 13 marks Finite Equally-Likely Probability Computation View
A supermarket randomly selected 1000 customers and recorded their purchasing of four products: A, B, C, and D. The data is organized in the table below, where ``✓'' indicates purchase and ``×'' indicates no purchase.\n\n\n
\n\n\backslashbox{Number of Customers}{Product}ABCD
\n\n100×
\n\n217××
\n\n200×
\n\n300××
\n\n85×××
\n\n98×××
\n\n
\n\n\n(I) Estimate the probability that a customer purchases both B and C\n(II) Estimate the probability that a customer purchases exactly 3 of the four products A, B, C, and D\n(III) If a customer has purchased product A, which of products B, C, and D is the customer most likely to have purchased?