Advertisements
Advertisements
Question
A college awarded 38 medals in volleyball, 15 in football, and 20 in basketball. The medals awarded to a total of 58 players and only 3 players got medals in all three sports. How many received medals in exactly two of the three sports?
Advertisements
Solution
Let A = Set of students who received medals in volleyball.
B = Set of students who received medals in football.
C = Set of students who received medals in basketball.
n(A) = 38, n(B) = 15, n (C) = 20, n(A ∪ B ∪ C) = 58, n(A ∩ B ∩ C) = 3.
n(A ∪ B ∪ C)
= n(A) + n(B) + n(C) − n(A ∩ B) − n(B ∩ C) − n(A ∩ C) + n(A ∩ B ∩ C)
∴ 58 = 38 + 15 + 20 − n(A ∩ B) − n(B ∩ C) − n(A ∩ C) + 3
∴ n(A ∩ B) + n(B ∩ C) + n(A ∩ C) = 18 .......(i)
Number of players who got exactly two medals = p + q + r
Here, s = n(A ∩ B ∩ C) = 3
n(A ∩ B) + n(B ∩ C) + n(A ∩ C) = 18 …[From (i)]
∴ p + s + s + r + q + s = 18
∴ p + q + r + 3s = 18
∴ p + q + r + 3(3) = 18
∴ p + q + r = 18 − 9 = 9
∴ Number of players who received exactly two medals = 9.
APPEARS IN
RELATED QUESTIONS
Identify whether the following is set or not? Justify your answer.
The collection of all natural numbers less than 100.
Write the following set in roster form:
F = The set of all letters in the word BETTER
Write the following set in the set-builder form:
{3, 6, 9, 12}
List all the elements of the following set:
E = {x : x is a month of a year not having 31 days}
Which of the following collection are sets? Justify your answer:
The collection of all girls in your class.
Which of the following collection are sets? Justify your answer:
The collection of prime integers.
If A = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10], then insert the appropriate symbol ∈ or ∉ in each of the following blank space:
4 ...... A
If A = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10], then insert the appropriate symbol ∈ or ∉ in each of the following blank space:
0 ...... A
Describe the following sets in Roster form:
The set of all letters in the word 'Better'.
Describe the following sets in Roster form:
The set of all letters in the word 'Better'.
Describe the following sets in set-builder form:
A = {1, 2, 3, 4, 5, 6}
Describe the following sets in set-builder form:
D = {10, 11, 12, 13, 14, 15};
Describe the following sets in set-builder form:
E = {0}
Describe the following sets in set-builder form:
{1, 4, 9, 16, ..., 100}
List all the elements of the following set:
\[C = \left\{ x: x \text{ is an integer }, - \frac{1}{2} < x < \frac{9}{2} \right\}\]
List all the elements of the following set:
D = {x : x is a vowel in the word "EQUATION"}
Write the set \[\left\{ \frac{1}{2}, \frac{2}{5}, \frac{3}{10}, \frac{4}{17}, \frac{5}{26}, \frac{6}{37}, \frac{7}{50} \right\}\] in the set-builder form.
Which of the following statement are correct?
Write a correct form of each of the incorrect statement.
\[\left\{ a \right\} \in \left\{ a, b, c \right\}\]
Which of the following statemen are correct?
Write a correct form of each of the incorrect statement.
\[\left\{ a, b \right\} \subset \left\{ a, \left\{ b, c \right\} \right\}\]
Which of the following statement are correct?
Write a correct form of each of the incorrect statement.
\[\left\{ a, b \right\} \subset \left\{ a, \left\{ b, c \right\} \right\}\]
Which of the following statement are correct?
Write a correct form of each of the incorrect statement.
\[\left\{ a, b \right\} \subset \left\{ a, \left\{ b, c \right\} \right\}\]
Let A = {a, b, {c, d}, e}. Which of the following statement are false and why?
\[\left\{ \left\{ c, d \right\} \right\} \subset A\]
Let A = {a, b, {c, d}, e}. Which of the following statement are false and why?
\[\phi \in A\]
Let A = {{1, 2, 3}, {4, 5}, {6, 7, 8}}. Determine which of the following is true or false:
\[1 \in A\]
Let\[A = \left\{ \phi, \left\{ \phi \right\}, 1, \left\{ 1, \phi \right\}, 2 \right\}\] Which of the following are true?
Write down all possible subsets of each of the following set:
{a}
Write down all possible proper subsets each of the following set:
{1, 2},
Write down all possible proper subsets each of the following set:
{1}.
Let A = {1, 2, 3, 4, 5, 6}. Insert the appropriate symbol ∈ or ∉ in the blank space:
2 _____ A
Describe the following set in Set-Builder form
{0}
Write the following interval in Set-Builder form.
(2, 5]
Let X = {1, 2, 3, 4, 5, 6}. If n represent any member of X, express the following as sets:
n is greater than 4
Write the following sets in the roaster form:
D = {t | t3 = t, t ∈ R}
State which of the following statement is true and which is false. Justify your answer.
35 ∈ {x | x has exactly four positive factors}.
State which of the following statement is true and which is false. Justify your answer.
3 ∉ {x | x4 – 5x3 + 2x2 – 112x + 6 = 0}
In a group of 50 students, the number of students studying French, English, Sanskrit were found to be as follows:
French = 17, English = 13, Sanskrit = 15 French and English = 09, English and Sanskrit = 4 French and Sanskrit = 5, English, French and Sanskrit = 3. Find the number of students who study French and Sanskrit but not English
If A and B are any two sets, then A – B is equal to ______.
